Mental Ability: Patterns, Logic, and Codes
Core skills
Mental Ability questions reward pattern recognition more than calculation. Expect number series, letter series, analogies, classification, coding-decoding, logical deduction, and spatial reasoning. For series, check simple differences first, then ratios, then alternating or two-step rules. For analogies, state the relationship in a precise sentence before choosing an option. For deductions, separate what must be true from what could be true. For spatial items, rotate or fold mentally in small steps and track one feature at a time.
Common traps
The biggest trap is assuming the first pattern you notice is the only one. A series may alternate between two rules, or a code may shift letters by changing amounts. Another trap is choosing an answer that is merely plausible in a deduction question but not forced by the premises. Watch for distractors that continue a pattern for one step but break later. In classification questions, check every option against the stated category, not just the first two.
Rule of thumb
When a sequence looks irregular, write the differences underneath; if those are irregular, write their differences. For letter series, convert letters to positions (A=1, B=2, ...). For coding, test the same rule on every word, not just the first.
Worked example
Find the next term: 2, 6, 12, 20, 30. Differences are 4, 6, 8, 10, so the next difference is 12. The next term is 30 + 12 = 42.