Intelligence and Reasoning: Series, Codes and Non-Verbal Items
The Intelligence and Reasoning section measures pattern-spotting, not learned facts. Typical items are number and letter series, analogies, odd-one-out, coding-decoding, direction sense, blood relations and non-verbal figures such as mirror images, rotation and paper folding.
Approach by type
- Number series: write the differences between terms. Growing differences mean a quadratic pattern; squares and primes often fit.
- Letter series: convert letters to positions (A = 1 to Z = 26), then check whether alternate letters form two separate series.
- Coding: compare the plain word and the code letter by letter to find the shift, then apply the same shift.
- Direction: draw a small compass sketch; a left or right turn is taken relative to the direction you currently face.
- Blood relations: draw a family tree, marking male and female, instead of holding it in your head.
- Mirror image: left and right swap, top and bottom do not. A water image swaps top and bottom.
Worked example
Series: 2, 6, 12, 20, 30, ? Differences: 4, 6, 8, 10, increasing by 2 each time, so the next difference is 12 and the answer is 30 + 12 = 42. Check with the term rule n x (n + 1): 6 x 7 = 42, which confirms it.
Traps
- Guessing a pattern from only the first two terms; test it on every term.
- Missing that an item contains two interleaved series.
- Counting holes in folded paper before it is opened.
- Spending several minutes on one item instead of marking it and returning later.