Reasoning and General Intelligence
Core topics
Reasoning is scored by pattern-recognition speed, not by knowledge. Expect number and letter series; analogies and odd-one-out; coding-decoding (letter shifting, substitution, conditional coding); blood relations; direction and distance; ranking and ordering; syllogism; linear and circular seating with facing directions; puzzles; and non-verbal items - mirror and water images, paper folding and cutting, embedded figures, figure series, dice and cube counting.
Traps
Syllogism items use 'only a few', 'some not' and 'no' to break standard Venn conclusions - draw the diagram instead of guessing. In direction sense the common error is turning right while facing west and writing east; always draw a compass rose. In blood relations, 'my mother's only son's wife' traps solvers who forget they may be the person described. In letter series, fix positions with EJOTY: E=5, J=10, O=15, T=20, Y=25. In circular seating, 'facing outside' reverses left and right.
Worked example
Series: 2, 6, 12, 20, 30, ? Take successive differences: 4, 6, 8, 10 - an arithmetic progression, so the next difference is 12 and the answer is 42. Equivalently the terms are n(n+1). Always test differences first, then ratios, then squares and cubes, before assuming a two-line rule.
Rule of thumb: spend under 45 seconds on any reasoning item; the section rewards breadth, so mark and move rather than sinking time into one puzzle.