Reasoning for JKSSB Exams: Every Topic Explained with Worked Examples

Reasoning questions in JKSSB papers are short, and most of them can be solved in under a minute once you know the method for each type. Reasoning rewards practice more than reading, because the skill is recognising a pattern quickly. This guide goes through the main topics, gives a method for each, and works through an example.

1. Number series

Look at the differences between consecutive terms first. If the differences are constant, it is an arithmetic series. If the differences themselves form a pattern, look at the second differences. Also check for squares, cubes, multiplication by a fixed number, or alternating patterns.

Example: 2, 6, 12, 20, 30, ? The differences are 4, 6, 8, 10, which increase by 2. The next difference is 12, so the next term is 30 + 12 = 42. (The terms are also n × (n + 1).)

2. Letter series and alphabet position

Write the position of each letter (A = 1, B = 2 and so on) and treat the letters like numbers. Remember that the position of a letter from the end is 27 minus its position from the start.

Example: B, E, H, K, ? The positions are 2, 5, 8, 11, and the difference is 3. The next position is 14, which is N.

3. Coding-decoding

Find the rule by comparing a word with its code letter by letter. Common rules are a fixed shift forward or backward, reversing the word, or replacing letters with numbers.

Example: If CAT is coded as ECV, how is DOG coded? Each letter moves two places forward: C to E, A to C, T to V. Applying the same shift to D, O, G gives F, Q, I, so DOG is coded as FQI.

4. Blood relations

Draw a small family tree and work from the clue closest to the person you are asked about. Use symbols: a circle for a female, a square for a male, a line for marriage and a vertical line for a child. Read the statement slowly, because 'my mother's only son' means the speaker's brother, and 'my father's only daughter' can mean the speaker herself.

Example: Pointing to a man, Rita says, 'He is the son of my mother's only son.' How is the man related to Rita? Rita's mother's only son is Rita's brother. The man is the son of Rita's brother, so he is Rita's nephew.

5. Direction sense

Draw the path on paper with north at the top. Right from north is east, and left from north is west. Compute the final position as the difference of north-south moves and east-west moves, then use the Pythagorean theorem for the straight-line distance if needed.

Example: Ravi walks 5 km north, turns right and walks 3 km, then turns right again and walks 5 km. How far and in which direction is he from the start? Walking north 5 km and then south 5 km cancels out, leaving 3 km to the east. He is 3 km east of the start.

6. Ranking and order

For a position counted from one end, the position from the other end is the total number of people plus 1, minus the given position. For two positions in the same row, the number of people between them is the difference of positions minus 1.

Example: In a row of 30 students, Meena is 12th from the left. What is her position from the right? 30 − 12 + 1 = 19th.

7. Classification (odd one out)

Find the property shared by most items and spot the one that does not have it. Check for category (fruit, vegetable), number properties (prime, even, square) and word properties (number of letters, vowels).

Example: Mango, Apple, Potato, Banana. Mango, apple and banana are fruits, while potato is a vegetable. The odd one out is Potato.

8. Syllogisms and statements

Draw Venn diagrams for each statement. 'All A are B' puts circle A inside circle B. 'Some A are B' overlaps the circles. A conclusion follows only if it is true in every possible diagram.

Example: Statements: All pens are books. Some books are bags. Conclusions: I. Some pens are bags. II. Some bags are books. The second conclusion is the reverse of 'some books are bags' and always holds. The first does not have to hold, because the pens inside the books may not overlap with the bags. Only conclusion II follows.

9. Calendar and clock

An ordinary year has 365 days, which is 52 weeks and 1 odd day. A leap year has 2 odd days. So the same date moves forward by one weekday in an ordinary year and by two after a leap day.

Example: 1 January 2026 is a Thursday. What day is 1 January 2027? The year 2026 is not a leap year, so the date moves forward by one day. It is a Friday.

10. Mathematical operations with changed symbols

Replace the symbols with their real meaning first, then apply BODMAS. Do not try to solve with the symbols as written.

Example: If + means ×, − means +, and × means −, what is 6 + 3 − 4 × 2? Replace the symbols: 6 × 3 + 4 − 2. Multiplication first: 18 + 4 − 2 = 20.

How to practise reasoning

• Take one topic at a time and solve 15 to 20 questions at the Easy level, then Medium
• Time yourself: most reasoning questions should take 30 to 60 seconds
• Keep a notebook of the patterns that confused you and revisit it every weekend
• Mix topics in subject tests only after each topic is comfortable

Practise by topic in the reasoning topic sets, and read the guides on coding-decoding, analogy and problems on ages.