Logical Reasoning and Abstract Problem Solving
What this domain tests
Logical and abstract reasoning tests rule discovery: number and letter series, coding-decoding, syllogisms, seating and ordering puzzles, matrices, figure rotation and odd-one-out. You are assessed on valid deduction, not on guessing patterns that fit only one term.
Core rules
- In series, test the rule on every transition; check differences, ratios, alternating sub-series and squares or cubes.
- In coding, write the alphabet with positions 1 to 26 and track shifts separately for each letter.
- In syllogisms, draw Venn diagrams. 'Some A are B' does not imply 'some B are not A'; only apply what the premises force.
- In matrices, check rows and columns separately for movement, shading, rotation and count.
- In spatial items, distinguish rotation from reflection; a mirror image reverses handedness.
Worked example
Find the next term: 3, 6, 11, 18, 27, ? Differences: 3, 5, 7, 9, which are consecutive odd numbers. The next difference is 11, so the answer is 38. Check: 27 + 11 = 38. A rule such as 'add 3, then 5, then 7' must explain all transitions, not just the first two.
Traps
Overfitting a rule to one pair; ignoring a second interleaved series; treating 'some' as 'all'; assuming a figure rotated when it was reflected; and spending too long on one item. If a rule fails on any term, discard it.
Method
For each item, state the candidate rule in words, test it on the next transition, then answer. Mark uncertain items and return only after securing the straightforward ones.