General Intelligence and Reasoning
General Intelligence and Reasoning is usually the highest-scoring section of JSSC CGL because it is rule-based and needs no factual memory. The recurring families are number and letter series, analogy, classification (odd one out), coding-decoding, blood relations, direction sense, syllogism, seating and ranking puzzles, and non-verbal figure series.
Rules to keep ready
- Series: test differences, then ratios, then squares and cubes with a constant offset. Check two interleaved series when alternate terms behave differently.
- Coding-decoding: write the alphabet with positions 1 to 26 and note the offset between letters of the code and the word.
- Blood relations: draw a family tree with symbols for male, female, marriage and siblings; never solve in your head.
- Syllogism: draw Venn diagrams for the statements and test each conclusion against every possible diagram; a conclusion is valid only if it holds in all diagrams.
- Direction sense: always draw compass directions and track net displacement.
Worked example
Question: Find the next term: 3, 8, 15, 24, ? Reasoning: the terms equal n² − 1 for n = 2, 3, 4, 5. Verify: 4 − 1 = 3, 9 − 1 = 8, 16 − 1 = 15, 25 − 1 = 24. The next term uses n = 6, giving 36 − 1 = 35. Alternatively, the differences are 5, 7, 9, so the next difference is 11 and 24 + 11 = 35. Answer: 35.
Traps that cost marks
- Assuming a series is arithmetic when alternate terms form two different patterns.
- Treating a possibility as a certainty in syllogism - only forced conclusions count.
- Missing the direction of a turn (left versus right) when a person faces south instead of north.