General Aptitude and Reasoning
General Aptitude and Reasoning is scoring because every item follows a rule; marks are lost to haste rather than ignorance.
Core types
- Series: test differences first, then ratios, then alternating, prime or square patterns.
- Coding–decoding: map letter positions (A = 1 … Z = 26) and check simple shifts before assuming reversal.
- Blood relations: draw a family tree, mark male/female symbols, and never infer gender from a name.
- Direction sense: sketch axes; a left turn while facing south points east.
- Syllogism: use Venn diagrams; 'All A are B' does not convert to 'All B are A', though 'Some A are B' converts to 'Some B are A'.
- Arithmetic: percentage change = (new − old)/old × 100; for equal distances, average speed = 2xy/(x + y).
Worked example
Series: 2, 6, 12, 20, 30, ?. First differences are 4, 6, 8, 10 - an arithmetic progression rising by 2 - so the next difference is 12 and the term is 42. The same series is n(n + 1): 1·2, 2·3, 3·4, 4·5, 5·6, and the sixth term is 6 × 7 = 42. Confirming an answer by two independent routes is the reliable habit here.
Traps
Treating percentage points as per cent; averaging speeds arithmetically instead of harmonically; comparing ratios without converting to common units; rejecting a 'possibility' conclusion because it is not certain; forgetting that 'only a few A are B' leaves the remaining A outside B.