Small Group Tutorials

Here to help students catch up, keep up, and move ahead. Book a consultation here.

How to Perform in the new G2 SEC Examinations | Learner’s Guide Vol 0136 | Branch-and-Bound Elimination — Remove Impossible Paths Before You Fully Solve Them

G2 SEC examination problems often become easier when learners eliminate impossible branches before fully solving every possibility. A unit, bound, source restriction, chronology rule or domain condition can prune whole families of answers.

This one-hundred-and-thirty-sixth Learner’s Guide develops branch-and-bound elimination across K200 English, K210 Mathematics and K223–K225 Science. It builds on Vol 0132 Option Value and Vol 0124 Constraint Stack.

The branch-and-bound protocol

Generate only plausible candidates, then apply the cheapest hard constraints first. Eliminate branches that violate units, source, chronology, domain, bounds or explicit conditions. Spend deeper reasoning only on survivors.

1. MCQ impossible unit

For MCQ impossible unit, list the candidate branches and identify one hard bound capable of eliminating at least one branch without completing every calculation or interpretation.

For practice, rank the available tests by cost and pruning power. A good early test is cheap and removes many candidates. A costly test that distinguishes only two already unlikely branches should usually wait.

Never eliminate a branch using a soft preference as if it were a hard rule. If the evidence only makes a candidate less likely, keep it available until a genuine contradiction, bound or stronger comparison closes it.

2. MCQ impossible sign

For MCQ impossible sign, list the candidate branches and identify one hard bound capable of eliminating at least one branch without completing every calculation or interpretation.

For practice, rank the available tests by cost and pruning power. A good early test is cheap and removes many candidates. A costly test that distinguishes only two already unlikely branches should usually wait.

Never eliminate a branch using a soft preference as if it were a hard rule. If the evidence only makes a candidate less likely, keep it available until a genuine contradiction, bound or stronger comparison closes it.

3. MCQ impossible magnitude

For MCQ impossible magnitude, list the candidate branches and identify one hard bound capable of eliminating at least one branch without completing every calculation or interpretation.

For practice, rank the available tests by cost and pruning power. A good early test is cheap and removes many candidates. A costly test that distinguishes only two already unlikely branches should usually wait.

Never eliminate a branch using a soft preference as if it were a hard rule. If the evidence only makes a candidate less likely, keep it available until a genuine contradiction, bound or stronger comparison closes it.

4. MCQ wrong source

For MCQ wrong source, list the candidate branches and identify one hard bound capable of eliminating at least one branch without completing every calculation or interpretation.

For practice, rank the available tests by cost and pruning power. A good early test is cheap and removes many candidates. A costly test that distinguishes only two already unlikely branches should usually wait.

Never eliminate a branch using a soft preference as if it were a hard rule. If the evidence only makes a candidate less likely, keep it available until a genuine contradiction, bound or stronger comparison closes it.

5. MCQ wrong chronology

For MCQ wrong chronology, list the candidate branches and identify one hard bound capable of eliminating at least one branch without completing every calculation or interpretation.

For practice, rank the available tests by cost and pruning power. A good early test is cheap and removes many candidates. A costly test that distinguishes only two already unlikely branches should usually wait.

Never eliminate a branch using a soft preference as if it were a hard rule. If the evidence only makes a candidate less likely, keep it available until a genuine contradiction, bound or stronger comparison closes it.

6. MCQ wrong quantifier

For MCQ wrong quantifier, list the candidate branches and identify one hard bound capable of eliminating at least one branch without completing every calculation or interpretation.

For practice, rank the available tests by cost and pruning power. A good early test is cheap and removes many candidates. A costly test that distinguishes only two already unlikely branches should usually wait.

Never eliminate a branch using a soft preference as if it were a hard rule. If the evidence only makes a candidate less likely, keep it available until a genuine contradiction, bound or stronger comparison closes it.

7. MCQ wrong modality

For MCQ wrong modality, list the candidate branches and identify one hard bound capable of eliminating at least one branch without completing every calculation or interpretation.

For practice, rank the available tests by cost and pruning power. A good early test is cheap and removes many candidates. A costly test that distinguishes only two already unlikely branches should usually wait.

Never eliminate a branch using a soft preference as if it were a hard rule. If the evidence only makes a candidate less likely, keep it available until a genuine contradiction, bound or stronger comparison closes it.

8. MCQ wrong denominator

For MCQ wrong denominator, list the candidate branches and identify one hard bound capable of eliminating at least one branch without completing every calculation or interpretation.

For practice, rank the available tests by cost and pruning power. A good early test is cheap and removes many candidates. A costly test that distinguishes only two already unlikely branches should usually wait.

Never eliminate a branch using a soft preference as if it were a hard rule. If the evidence only makes a candidate less likely, keep it available until a genuine contradiction, bound or stronger comparison closes it.

9. MCQ wrong graph interval

For MCQ wrong graph interval, list the candidate branches and identify one hard bound capable of eliminating at least one branch without completing every calculation or interpretation.

For practice, rank the available tests by cost and pruning power. A good early test is cheap and removes many candidates. A costly test that distinguishes only two already unlikely branches should usually wait.

Never eliminate a branch using a soft preference as if it were a hard rule. If the evidence only makes a candidate less likely, keep it available until a genuine contradiction, bound or stronger comparison closes it.

10. MCQ wrong domain

For MCQ wrong domain, list the candidate branches and identify one hard bound capable of eliminating at least one branch without completing every calculation or interpretation.

For practice, rank the available tests by cost and pruning power. A good early test is cheap and removes many candidates. A costly test that distinguishes only two already unlikely branches should usually wait.

Never eliminate a branch using a soft preference as if it were a hard rule. If the evidence only makes a candidate less likely, keep it available until a genuine contradiction, bound or stronger comparison closes it.

11. English referent candidate

For English referent candidate, list the candidate branches and identify one hard bound capable of eliminating at least one branch without completing every calculation or interpretation.

For practice, rank the available tests by cost and pruning power. A good early test is cheap and removes many candidates. A costly test that distinguishes only two already unlikely branches should usually wait.

Never eliminate a branch using a soft preference as if it were a hard rule. If the evidence only makes a candidate less likely, keep it available until a genuine contradiction, bound or stronger comparison closes it.

12. English meaning candidate

For English meaning candidate, list the candidate branches and identify one hard bound capable of eliminating at least one branch without completing every calculation or interpretation.

For practice, rank the available tests by cost and pruning power. A good early test is cheap and removes many candidates. A costly test that distinguishes only two already unlikely branches should usually wait.

Never eliminate a branch using a soft preference as if it were a hard rule. If the evidence only makes a candidate less likely, keep it available until a genuine contradiction, bound or stronger comparison closes it.

13. English inference candidate

For English inference candidate, list the candidate branches and identify one hard bound capable of eliminating at least one branch without completing every calculation or interpretation.

For practice, rank the available tests by cost and pruning power. A good early test is cheap and removes many candidates. A costly test that distinguishes only two already unlikely branches should usually wait.

Never eliminate a branch using a soft preference as if it were a hard rule. If the evidence only makes a candidate less likely, keep it available until a genuine contradiction, bound or stronger comparison closes it.

14. English tone candidate

For English tone candidate, list the candidate branches and identify one hard bound capable of eliminating at least one branch without completing every calculation or interpretation.

For practice, rank the available tests by cost and pruning power. A good early test is cheap and removes many candidates. A costly test that distinguishes only two already unlikely branches should usually wait.

Never eliminate a branch using a soft preference as if it were a hard rule. If the evidence only makes a candidate less likely, keep it available until a genuine contradiction, bound or stronger comparison closes it.

15. English purpose candidate

For English purpose candidate, list the candidate branches and identify one hard bound capable of eliminating at least one branch without completing every calculation or interpretation.

For practice, rank the available tests by cost and pruning power. A good early test is cheap and removes many candidates. A costly test that distinguishes only two already unlikely branches should usually wait.

Never eliminate a branch using a soft preference as if it were a hard rule. If the evidence only makes a candidate less likely, keep it available until a genuine contradiction, bound or stronger comparison closes it.

16. English source candidate

For English source candidate, list the candidate branches and identify one hard bound capable of eliminating at least one branch without completing every calculation or interpretation.

For practice, rank the available tests by cost and pruning power. A good early test is cheap and removes many candidates. A costly test that distinguishes only two already unlikely branches should usually wait.

Never eliminate a branch using a soft preference as if it were a hard rule. If the evidence only makes a candidate less likely, keep it available until a genuine contradiction, bound or stronger comparison closes it.

17. English chronology candidate

For English chronology candidate, list the candidate branches and identify one hard bound capable of eliminating at least one branch without completing every calculation or interpretation.

For practice, rank the available tests by cost and pruning power. A good early test is cheap and removes many candidates. A costly test that distinguishes only two already unlikely branches should usually wait.

Never eliminate a branch using a soft preference as if it were a hard rule. If the evidence only makes a candidate less likely, keep it available until a genuine contradiction, bound or stronger comparison closes it.

18. English summary point

For English summary point, list the candidate branches and identify one hard bound capable of eliminating at least one branch without completing every calculation or interpretation.

For practice, rank the available tests by cost and pruning power. A good early test is cheap and removes many candidates. A costly test that distinguishes only two already unlikely branches should usually wait.

Never eliminate a branch using a soft preference as if it were a hard rule. If the evidence only makes a candidate less likely, keep it available until a genuine contradiction, bound or stronger comparison closes it.

19. English writing example

For English writing example, list the candidate branches and identify one hard bound capable of eliminating at least one branch without completing every calculation or interpretation.

For practice, rank the available tests by cost and pruning power. A good early test is cheap and removes many candidates. A costly test that distinguishes only two already unlikely branches should usually wait.

Never eliminate a branch using a soft preference as if it were a hard rule. If the evidence only makes a candidate less likely, keep it available until a genuine contradiction, bound or stronger comparison closes it.

20. English paragraph route

For English paragraph route, list the candidate branches and identify one hard bound capable of eliminating at least one branch without completing every calculation or interpretation.

For practice, rank the available tests by cost and pruning power. A good early test is cheap and removes many candidates. A costly test that distinguishes only two already unlikely branches should usually wait.

Never eliminate a branch using a soft preference as if it were a hard rule. If the evidence only makes a candidate less likely, keep it available until a genuine contradiction, bound or stronger comparison closes it.

21. Math root candidate

For Math root candidate, list the candidate branches and identify one hard bound capable of eliminating at least one branch without completing every calculation or interpretation.

For practice, rank the available tests by cost and pruning power. A good early test is cheap and removes many candidates. A costly test that distinguishes only two already unlikely branches should usually wait.

Never eliminate a branch using a soft preference as if it were a hard rule. If the evidence only makes a candidate less likely, keep it available until a genuine contradiction, bound or stronger comparison closes it.

22. Math case branch

For Math case branch, list the candidate branches and identify one hard bound capable of eliminating at least one branch without completing every calculation or interpretation.

For practice, rank the available tests by cost and pruning power. A good early test is cheap and removes many candidates. A costly test that distinguishes only two already unlikely branches should usually wait.

Never eliminate a branch using a soft preference as if it were a hard rule. If the evidence only makes a candidate less likely, keep it available until a genuine contradiction, bound or stronger comparison closes it.

23. Math formula candidate

For Math formula candidate, list the candidate branches and identify one hard bound capable of eliminating at least one branch without completing every calculation or interpretation.

For practice, rank the available tests by cost and pruning power. A good early test is cheap and removes many candidates. A costly test that distinguishes only two already unlikely branches should usually wait.

Never eliminate a branch using a soft preference as if it were a hard rule. If the evidence only makes a candidate less likely, keep it available until a genuine contradiction, bound or stronger comparison closes it.

24. Math representation candidate

For Math representation candidate, list the candidate branches and identify one hard bound capable of eliminating at least one branch without completing every calculation or interpretation.

For practice, rank the available tests by cost and pruning power. A good early test is cheap and removes many candidates. A costly test that distinguishes only two already unlikely branches should usually wait.

Never eliminate a branch using a soft preference as if it were a hard rule. If the evidence only makes a candidate less likely, keep it available until a genuine contradiction, bound or stronger comparison closes it.

25. Math answer option

For Math answer option, list the candidate branches and identify one hard bound capable of eliminating at least one branch without completing every calculation or interpretation.

For practice, rank the available tests by cost and pruning power. A good early test is cheap and removes many candidates. A costly test that distinguishes only two already unlikely branches should usually wait.

Never eliminate a branch using a soft preference as if it were a hard rule. If the evidence only makes a candidate less likely, keep it available until a genuine contradiction, bound or stronger comparison closes it.

26. Math integer candidate

For Math integer candidate, list the candidate branches and identify one hard bound capable of eliminating at least one branch without completing every calculation or interpretation.

For practice, rank the available tests by cost and pruning power. A good early test is cheap and removes many candidates. A costly test that distinguishes only two already unlikely branches should usually wait.

Never eliminate a branch using a soft preference as if it were a hard rule. If the evidence only makes a candidate less likely, keep it available until a genuine contradiction, bound or stronger comparison closes it.

27. Math geometric configuration

For Math geometric configuration, list the candidate branches and identify one hard bound capable of eliminating at least one branch without completing every calculation or interpretation.

For practice, rank the available tests by cost and pruning power. A good early test is cheap and removes many candidates. A costly test that distinguishes only two already unlikely branches should usually wait.

Never eliminate a branch using a soft preference as if it were a hard rule. If the evidence only makes a candidate less likely, keep it available until a genuine contradiction, bound or stronger comparison closes it.

28. Math probability branch

For Math probability branch, list the candidate branches and identify one hard bound capable of eliminating at least one branch without completing every calculation or interpretation.

For practice, rank the available tests by cost and pruning power. A good early test is cheap and removes many candidates. A costly test that distinguishes only two already unlikely branches should usually wait.

Never eliminate a branch using a soft preference as if it were a hard rule. If the evidence only makes a candidate less likely, keep it available until a genuine contradiction, bound or stronger comparison closes it.

29. Math bound interval

For Math bound interval, list the candidate branches and identify one hard bound capable of eliminating at least one branch without completing every calculation or interpretation.

For practice, rank the available tests by cost and pruning power. A good early test is cheap and removes many candidates. A costly test that distinguishes only two already unlikely branches should usually wait.

Never eliminate a branch using a soft preference as if it were a hard rule. If the evidence only makes a candidate less likely, keep it available until a genuine contradiction, bound or stronger comparison closes it.

30. Math unit conversion direction

For Math unit conversion direction, list the candidate branches and identify one hard bound capable of eliminating at least one branch without completing every calculation or interpretation.

For practice, rank the available tests by cost and pruning power. A good early test is cheap and removes many candidates. A costly test that distinguishes only two already unlikely branches should usually wait.

Never eliminate a branch using a soft preference as if it were a hard rule. If the evidence only makes a candidate less likely, keep it available until a genuine contradiction, bound or stronger comparison closes it.

31. Math comparison measure

For Math comparison measure, list the candidate branches and identify one hard bound capable of eliminating at least one branch without completing every calculation or interpretation.

For practice, rank the available tests by cost and pruning power. A good early test is cheap and removes many candidates. A costly test that distinguishes only two already unlikely branches should usually wait.

Never eliminate a branch using a soft preference as if it were a hard rule. If the evidence only makes a candidate less likely, keep it available until a genuine contradiction, bound or stronger comparison closes it.

32. Math breakpoint region

For Math breakpoint region, list the candidate branches and identify one hard bound capable of eliminating at least one branch without completing every calculation or interpretation.

For practice, rank the available tests by cost and pruning power. A good early test is cheap and removes many candidates. A costly test that distinguishes only two already unlikely branches should usually wait.

Never eliminate a branch using a soft preference as if it were a hard rule. If the evidence only makes a candidate less likely, keep it available until a genuine contradiction, bound or stronger comparison closes it.

33. Math parameter candidate

For Math parameter candidate, list the candidate branches and identify one hard bound capable of eliminating at least one branch without completing every calculation or interpretation.

For practice, rank the available tests by cost and pruning power. A good early test is cheap and removes many candidates. A costly test that distinguishes only two already unlikely branches should usually wait.

Never eliminate a branch using a soft preference as if it were a hard rule. If the evidence only makes a candidate less likely, keep it available until a genuine contradiction, bound or stronger comparison closes it.

34. Science mechanism candidate

For Science mechanism candidate, list the candidate branches and identify one hard bound capable of eliminating at least one branch without completing every calculation or interpretation.

For practice, rank the available tests by cost and pruning power. A good early test is cheap and removes many candidates. A costly test that distinguishes only two already unlikely branches should usually wait.

Never eliminate a branch using a soft preference as if it were a hard rule. If the evidence only makes a candidate less likely, keep it available until a genuine contradiction, bound or stronger comparison closes it.

35. Science causal explanation

For Science causal explanation, list the candidate branches and identify one hard bound capable of eliminating at least one branch without completing every calculation or interpretation.

For practice, rank the available tests by cost and pruning power. A good early test is cheap and removes many candidates. A costly test that distinguishes only two already unlikely branches should usually wait.

Never eliminate a branch using a soft preference as if it were a hard rule. If the evidence only makes a candidate less likely, keep it available until a genuine contradiction, bound or stronger comparison closes it.

36. Science variable role

For Science variable role, list the candidate branches and identify one hard bound capable of eliminating at least one branch without completing every calculation or interpretation.

For practice, rank the available tests by cost and pruning power. A good early test is cheap and removes many candidates. A costly test that distinguishes only two already unlikely branches should usually wait.

Never eliminate a branch using a soft preference as if it were a hard rule. If the evidence only makes a candidate less likely, keep it available until a genuine contradiction, bound or stronger comparison closes it.

37. Science control explanation

For Science control explanation, list the candidate branches and identify one hard bound capable of eliminating at least one branch without completing every calculation or interpretation.

For practice, rank the available tests by cost and pruning power. A good early test is cheap and removes many candidates. A costly test that distinguishes only two already unlikely branches should usually wait.

Never eliminate a branch using a soft preference as if it were a hard rule. If the evidence only makes a candidate less likely, keep it available until a genuine contradiction, bound or stronger comparison closes it.

38. Science model

For Science model, list the candidate branches and identify one hard bound capable of eliminating at least one branch without completing every calculation or interpretation.

For practice, rank the available tests by cost and pruning power. A good early test is cheap and removes many candidates. A costly test that distinguishes only two already unlikely branches should usually wait.

Never eliminate a branch using a soft preference as if it were a hard rule. If the evidence only makes a candidate less likely, keep it available until a genuine contradiction, bound or stronger comparison closes it.

39. Science anomaly explanation

For Science anomaly explanation, list the candidate branches and identify one hard bound capable of eliminating at least one branch without completing every calculation or interpretation.

For practice, rank the available tests by cost and pruning power. A good early test is cheap and removes many candidates. A costly test that distinguishes only two already unlikely branches should usually wait.

Never eliminate a branch using a soft preference as if it were a hard rule. If the evidence only makes a candidate less likely, keep it available until a genuine contradiction, bound or stronger comparison closes it.

40. Science interaction model

For Science interaction model, list the candidate branches and identify one hard bound capable of eliminating at least one branch without completing every calculation or interpretation.

For practice, rank the available tests by cost and pruning power. A good early test is cheap and removes many candidates. A costly test that distinguishes only two already unlikely branches should usually wait.

Never eliminate a branch using a soft preference as if it were a hard rule. If the evidence only makes a candidate less likely, keep it available until a genuine contradiction, bound or stronger comparison closes it.

41. Science bottleneck candidate

For Science bottleneck candidate, list the candidate branches and identify one hard bound capable of eliminating at least one branch without completing every calculation or interpretation.

For practice, rank the available tests by cost and pruning power. A good early test is cheap and removes many candidates. A costly test that distinguishes only two already unlikely branches should usually wait.

Never eliminate a branch using a soft preference as if it were a hard rule. If the evidence only makes a candidate less likely, keep it available until a genuine contradiction, bound or stronger comparison closes it.

42. Science response-shape model

For Science response-shape model, list the candidate branches and identify one hard bound capable of eliminating at least one branch without completing every calculation or interpretation.

For practice, rank the available tests by cost and pruning power. A good early test is cheap and removes many candidates. A costly test that distinguishes only two already unlikely branches should usually wait.

Never eliminate a branch using a soft preference as if it were a hard rule. If the evidence only makes a candidate less likely, keep it available until a genuine contradiction, bound or stronger comparison closes it.

43. Science path-dependence hypothesis

For Science path-dependence hypothesis, list the candidate branches and identify one hard bound capable of eliminating at least one branch without completing every calculation or interpretation.

For practice, rank the available tests by cost and pruning power. A good early test is cheap and removes many candidates. A costly test that distinguishes only two already unlikely branches should usually wait.

Never eliminate a branch using a soft preference as if it were a hard rule. If the evidence only makes a candidate less likely, keep it available until a genuine contradiction, bound or stronger comparison closes it.

44. Science lag hypothesis

For Science lag hypothesis, list the candidate branches and identify one hard bound capable of eliminating at least one branch without completing every calculation or interpretation.

For practice, rank the available tests by cost and pruning power. A good early test is cheap and removes many candidates. A costly test that distinguishes only two already unlikely branches should usually wait.

Never eliminate a branch using a soft preference as if it were a hard rule. If the evidence only makes a candidate less likely, keep it available until a genuine contradiction, bound or stronger comparison closes it.

45. Science baseline-drift hypothesis

For Science baseline-drift hypothesis, list the candidate branches and identify one hard bound capable of eliminating at least one branch without completing every calculation or interpretation.

For practice, rank the available tests by cost and pruning power. A good early test is cheap and removes many candidates. A costly test that distinguishes only two already unlikely branches should usually wait.

Never eliminate a branch using a soft preference as if it were a hard rule. If the evidence only makes a candidate less likely, keep it available until a genuine contradiction, bound or stronger comparison closes it.

46. hard constraint pruning

For hard constraint pruning, list the candidate branches and identify one hard bound capable of eliminating at least one branch without completing every calculation or interpretation.

For practice, rank the available tests by cost and pruning power. A good early test is cheap and removes many candidates. A costly test that distinguishes only two already unlikely branches should usually wait.

Never eliminate a branch using a soft preference as if it were a hard rule. If the evidence only makes a candidate less likely, keep it available until a genuine contradiction, bound or stronger comparison closes it.

47. soft preference ranking

For soft preference ranking, list the candidate branches and identify one hard bound capable of eliminating at least one branch without completing every calculation or interpretation.

For practice, rank the available tests by cost and pruning power. A good early test is cheap and removes many candidates. A costly test that distinguishes only two already unlikely branches should usually wait.

Never eliminate a branch using a soft preference as if it were a hard rule. If the evidence only makes a candidate less likely, keep it available until a genuine contradiction, bound or stronger comparison closes it.

48. lower bound

For lower bound, list the candidate branches and identify one hard bound capable of eliminating at least one branch without completing every calculation or interpretation.

For practice, rank the available tests by cost and pruning power. A good early test is cheap and removes many candidates. A costly test that distinguishes only two already unlikely branches should usually wait.

Never eliminate a branch using a soft preference as if it were a hard rule. If the evidence only makes a candidate less likely, keep it available until a genuine contradiction, bound or stronger comparison closes it.

49. upper bound

For upper bound, list the candidate branches and identify one hard bound capable of eliminating at least one branch without completing every calculation or interpretation.

For practice, rank the available tests by cost and pruning power. A good early test is cheap and removes many candidates. A costly test that distinguishes only two already unlikely branches should usually wait.

Never eliminate a branch using a soft preference as if it were a hard rule. If the evidence only makes a candidate less likely, keep it available until a genuine contradiction, bound or stronger comparison closes it.

50. domain bound

For domain bound, list the candidate branches and identify one hard bound capable of eliminating at least one branch without completing every calculation or interpretation.

For practice, rank the available tests by cost and pruning power. A good early test is cheap and removes many candidates. A costly test that distinguishes only two already unlikely branches should usually wait.

Never eliminate a branch using a soft preference as if it were a hard rule. If the evidence only makes a candidate less likely, keep it available until a genuine contradiction, bound or stronger comparison closes it.

51. unit bound

For unit bound, list the candidate branches and identify one hard bound capable of eliminating at least one branch without completing every calculation or interpretation.

For practice, rank the available tests by cost and pruning power. A good early test is cheap and removes many candidates. A costly test that distinguishes only two already unlikely branches should usually wait.

Never eliminate a branch using a soft preference as if it were a hard rule. If the evidence only makes a candidate less likely, keep it available until a genuine contradiction, bound or stronger comparison closes it.

52. physical bound

For physical bound, list the candidate branches and identify one hard bound capable of eliminating at least one branch without completing every calculation or interpretation.

For practice, rank the available tests by cost and pruning power. A good early test is cheap and removes many candidates. A costly test that distinguishes only two already unlikely branches should usually wait.

Never eliminate a branch using a soft preference as if it were a hard rule. If the evidence only makes a candidate less likely, keep it available until a genuine contradiction, bound or stronger comparison closes it.

53. logical contradiction

For logical contradiction, list the candidate branches and identify one hard bound capable of eliminating at least one branch without completing every calculation or interpretation.

For practice, rank the available tests by cost and pruning power. A good early test is cheap and removes many candidates. A costly test that distinguishes only two already unlikely branches should usually wait.

Never eliminate a branch using a soft preference as if it were a hard rule. If the evidence only makes a candidate less likely, keep it available until a genuine contradiction, bound or stronger comparison closes it.

54. source contradiction

For source contradiction, list the candidate branches and identify one hard bound capable of eliminating at least one branch without completing every calculation or interpretation.

For practice, rank the available tests by cost and pruning power. A good early test is cheap and removes many candidates. A costly test that distinguishes only two already unlikely branches should usually wait.

Never eliminate a branch using a soft preference as if it were a hard rule. If the evidence only makes a candidate less likely, keep it available until a genuine contradiction, bound or stronger comparison closes it.

55. time contradiction

For time contradiction, list the candidate branches and identify one hard bound capable of eliminating at least one branch without completing every calculation or interpretation.

For practice, rank the available tests by cost and pruning power. A good early test is cheap and removes many candidates. A costly test that distinguishes only two already unlikely branches should usually wait.

Never eliminate a branch using a soft preference as if it were a hard rule. If the evidence only makes a candidate less likely, keep it available until a genuine contradiction, bound or stronger comparison closes it.

56. population contradiction

For population contradiction, list the candidate branches and identify one hard bound capable of eliminating at least one branch without completing every calculation or interpretation.

For practice, rank the available tests by cost and pruning power. A good early test is cheap and removes many candidates. A costly test that distinguishes only two already unlikely branches should usually wait.

Never eliminate a branch using a soft preference as if it were a hard rule. If the evidence only makes a candidate less likely, keep it available until a genuine contradiction, bound or stronger comparison closes it.

57. representation contradiction

For representation contradiction, list the candidate branches and identify one hard bound capable of eliminating at least one branch without completing every calculation or interpretation.

For practice, rank the available tests by cost and pruning power. A good early test is cheap and removes many candidates. A costly test that distinguishes only two already unlikely branches should usually wait.

Never eliminate a branch using a soft preference as if it were a hard rule. If the evidence only makes a candidate less likely, keep it available until a genuine contradiction, bound or stronger comparison closes it.

58. case exhaustion

For case exhaustion, list the candidate branches and identify one hard bound capable of eliminating at least one branch without completing every calculation or interpretation.

For practice, rank the available tests by cost and pruning power. A good early test is cheap and removes many candidates. A costly test that distinguishes only two already unlikely branches should usually wait.

Never eliminate a branch using a soft preference as if it were a hard rule. If the evidence only makes a candidate less likely, keep it available until a genuine contradiction, bound or stronger comparison closes it.

59. candidate ordering

For candidate ordering, list the candidate branches and identify one hard bound capable of eliminating at least one branch without completing every calculation or interpretation.

For practice, rank the available tests by cost and pruning power. A good early test is cheap and removes many candidates. A costly test that distinguishes only two already unlikely branches should usually wait.

Never eliminate a branch using a soft preference as if it were a hard rule. If the evidence only makes a candidate less likely, keep it available until a genuine contradiction, bound or stronger comparison closes it.

60. cheap elimination first

For cheap elimination first, list the candidate branches and identify one hard bound capable of eliminating at least one branch without completing every calculation or interpretation.

For practice, rank the available tests by cost and pruning power. A good early test is cheap and removes many candidates. A costly test that distinguishes only two already unlikely branches should usually wait.

Never eliminate a branch using a soft preference as if it were a hard rule. If the evidence only makes a candidate less likely, keep it available until a genuine contradiction, bound or stronger comparison closes it.

61. high-information test

For high-information test, list the candidate branches and identify one hard bound capable of eliminating at least one branch without completing every calculation or interpretation.

For practice, rank the available tests by cost and pruning power. A good early test is cheap and removes many candidates. A costly test that distinguishes only two already unlikely branches should usually wait.

Never eliminate a branch using a soft preference as if it were a hard rule. If the evidence only makes a candidate less likely, keep it available until a genuine contradiction, bound or stronger comparison closes it.

62. discriminating clue

For discriminating clue, list the candidate branches and identify one hard bound capable of eliminating at least one branch without completing every calculation or interpretation.

For practice, rank the available tests by cost and pruning power. A good early test is cheap and removes many candidates. A costly test that distinguishes only two already unlikely branches should usually wait.

Never eliminate a branch using a soft preference as if it were a hard rule. If the evidence only makes a candidate less likely, keep it available until a genuine contradiction, bound or stronger comparison closes it.

63. branch preservation

For branch preservation, list the candidate branches and identify one hard bound capable of eliminating at least one branch without completing every calculation or interpretation.

For practice, rank the available tests by cost and pruning power. A good early test is cheap and removes many candidates. A costly test that distinguishes only two already unlikely branches should usually wait.

Never eliminate a branch using a soft preference as if it were a hard rule. If the evidence only makes a candidate less likely, keep it available until a genuine contradiction, bound or stronger comparison closes it.

64. branch closure

For branch closure, list the candidate branches and identify one hard bound capable of eliminating at least one branch without completing every calculation or interpretation.

For practice, rank the available tests by cost and pruning power. A good early test is cheap and removes many candidates. A costly test that distinguishes only two already unlikely branches should usually wait.

Never eliminate a branch using a soft preference as if it were a hard rule. If the evidence only makes a candidate less likely, keep it available until a genuine contradiction, bound or stronger comparison closes it.

65. branch reopening

For branch reopening, list the candidate branches and identify one hard bound capable of eliminating at least one branch without completing every calculation or interpretation.

For practice, rank the available tests by cost and pruning power. A good early test is cheap and removes many candidates. A costly test that distinguishes only two already unlikely branches should usually wait.

Never eliminate a branch using a soft preference as if it were a hard rule. If the evidence only makes a candidate less likely, keep it available until a genuine contradiction, bound or stronger comparison closes it.

66. false elimination

For false elimination, list the candidate branches and identify one hard bound capable of eliminating at least one branch without completing every calculation or interpretation.

For practice, rank the available tests by cost and pruning power. A good early test is cheap and removes many candidates. A costly test that distinguishes only two already unlikely branches should usually wait.

Never eliminate a branch using a soft preference as if it were a hard rule. If the evidence only makes a candidate less likely, keep it available until a genuine contradiction, bound or stronger comparison closes it.

67. premature elimination

For premature elimination, list the candidate branches and identify one hard bound capable of eliminating at least one branch without completing every calculation or interpretation.

For practice, rank the available tests by cost and pruning power. A good early test is cheap and removes many candidates. A costly test that distinguishes only two already unlikely branches should usually wait.

Never eliminate a branch using a soft preference as if it were a hard rule. If the evidence only makes a candidate less likely, keep it available until a genuine contradiction, bound or stronger comparison closes it.

68. too many branches

For too many branches, list the candidate branches and identify one hard bound capable of eliminating at least one branch without completing every calculation or interpretation.

For practice, rank the available tests by cost and pruning power. A good early test is cheap and removes many candidates. A costly test that distinguishes only two already unlikely branches should usually wait.

Never eliminate a branch using a soft preference as if it were a hard rule. If the evidence only makes a candidate less likely, keep it available until a genuine contradiction, bound or stronger comparison closes it.

69. branch compression

For branch compression, list the candidate branches and identify one hard bound capable of eliminating at least one branch without completing every calculation or interpretation.

For practice, rank the available tests by cost and pruning power. A good early test is cheap and removes many candidates. A costly test that distinguishes only two already unlikely branches should usually wait.

Never eliminate a branch using a soft preference as if it were a hard rule. If the evidence only makes a candidate less likely, keep it available until a genuine contradiction, bound or stronger comparison closes it.

70. bound tightening

For bound tightening, list the candidate branches and identify one hard bound capable of eliminating at least one branch without completing every calculation or interpretation.

For practice, rank the available tests by cost and pruning power. A good early test is cheap and removes many candidates. A costly test that distinguishes only two already unlikely branches should usually wait.

Never eliminate a branch using a soft preference as if it were a hard rule. If the evidence only makes a candidate less likely, keep it available until a genuine contradiction, bound or stronger comparison closes it.

71. new evidence tightens bound

For new evidence tightens bound, list the candidate branches and identify one hard bound capable of eliminating at least one branch without completing every calculation or interpretation.

For practice, rank the available tests by cost and pruning power. A good early test is cheap and removes many candidates. A costly test that distinguishes only two already unlikely branches should usually wait.

Never eliminate a branch using a soft preference as if it were a hard rule. If the evidence only makes a candidate less likely, keep it available until a genuine contradiction, bound or stronger comparison closes it.

72. verification tightens bound

For verification tightens bound, list the candidate branches and identify one hard bound capable of eliminating at least one branch without completing every calculation or interpretation.

For practice, rank the available tests by cost and pruning power. A good early test is cheap and removes many candidates. A costly test that distinguishes only two already unlikely branches should usually wait.

Never eliminate a branch using a soft preference as if it were a hard rule. If the evidence only makes a candidate less likely, keep it available until a genuine contradiction, bound or stronger comparison closes it.

73. final candidate set

For final candidate set, list the candidate branches and identify one hard bound capable of eliminating at least one branch without completing every calculation or interpretation.

For practice, rank the available tests by cost and pruning power. A good early test is cheap and removes many candidates. A costly test that distinguishes only two already unlikely branches should usually wait.

Never eliminate a branch using a soft preference as if it were a hard rule. If the evidence only makes a candidate less likely, keep it available until a genuine contradiction, bound or stronger comparison closes it.

74. single survivor

For single survivor, list the candidate branches and identify one hard bound capable of eliminating at least one branch without completing every calculation or interpretation.

For practice, rank the available tests by cost and pruning power. A good early test is cheap and removes many candidates. A costly test that distinguishes only two already unlikely branches should usually wait.

Never eliminate a branch using a soft preference as if it were a hard rule. If the evidence only makes a candidate less likely, keep it available until a genuine contradiction, bound or stronger comparison closes it.

75. multiple survivors

For multiple survivors, list the candidate branches and identify one hard bound capable of eliminating at least one branch without completing every calculation or interpretation.

For practice, rank the available tests by cost and pruning power. A good early test is cheap and removes many candidates. A costly test that distinguishes only two already unlikely branches should usually wait.

Never eliminate a branch using a soft preference as if it were a hard rule. If the evidence only makes a candidate less likely, keep it available until a genuine contradiction, bound or stronger comparison closes it.

76. bounded answer

For bounded answer, list the candidate branches and identify one hard bound capable of eliminating at least one branch without completing every calculation or interpretation.

For practice, rank the available tests by cost and pruning power. A good early test is cheap and removes many candidates. A costly test that distinguishes only two already unlikely branches should usually wait.

Never eliminate a branch using a soft preference as if it were a hard rule. If the evidence only makes a candidate less likely, keep it available until a genuine contradiction, bound or stronger comparison closes it.

77. branch-and-bound final rule

For branch-and-bound final rule, list the candidate branches and identify one hard bound capable of eliminating at least one branch without completing every calculation or interpretation.

For practice, rank the available tests by cost and pruning power. A good early test is cheap and removes many candidates. A costly test that distinguishes only two already unlikely branches should usually wait.

Never eliminate a branch using a soft preference as if it were a hard rule. If the evidence only makes a candidate less likely, keep it available until a genuine contradiction, bound or stronger comparison closes it.

Bounding can be qualitative

A bound need not always be numerical. “Must come from Text 2”, “must occur before the decision”, “must be positive”, and “must explain the control result” are all constraints that can prune candidates.

Links

Use the Examination Craft hub, Vol 0128 Reversible vs Irreversible Moves, the relevant English, Mathematics and Science hubs, and the PSLE Learner’s Guide.

Official-source discipline

For the 2027 SEC G2 school-candidate framework, use the current SEAB G2 syllabus directory and linked subject syllabuses. Branch-and-bound elimination is an eduKateSengkang examination framework, not an SEAB marking label.

Final rule

Do not solve every branch equally. Use hard constraints to shrink the candidate set, preserve branches that remain genuinely possible, and spend deep effort only where the surviving alternatives still need separation.