Pariksha SaathiClassification Questions with Solutions (Odd One Out)
Classification questions give you a handful of items and ask which one doesn’t belong — the trick is finding the exact rule the majority share, not just going by a hunch. Here’s the approach, four fully worked examples covering the patterns that come up most, and a few to try yourself.
The approach, quickly
- Look for the rule that groups most of the items: a shared category, a shared mathematical property (prime, perfect square, even), a shared word-pattern, or a shared relationship between parts of each item.
- Check EVERY item against your hypothesized rule before answering — if your rule only explains 3 of 4 items and leaves a different one out than you expected, the rule itself is wrong, not just your answer.
- When items could be grouped more than one way, the correct rule is the one that cleanly separates exactly ONE item from the rest — if a rule leaves two items looking "odd", that’s not the intended rule.
- For pairs or sets of numbers, check the relationship within each pair first (ratio, difference, square, sum) before comparing across pairs — the odd one out usually breaks that specific internal relationship.
Worked examples
1. Find the odd one out: Mango, Banana, Carrot, Apple
Solution
- Mango, Banana and Apple are all fruits.
- Carrot is a vegetable, not a fruit — it doesn’t share the rule the other three follow.
Answer: Carrot
2. Find the odd one out: 7, 11, 15, 13
Solution
- 7, 11 and 13 are all prime numbers (divisible only by 1 and themselves).
- 15 = 3 × 5 is not prime — it’s composite, breaking the pattern.
Answer: 15
3. Find the odd one out: 24-6, 36-9, 45-9, 16-4
Solution
- Check the relationship within each pair: 24 ÷ 6 = 4, 36 ÷ 9 = 4, 45 ÷ 9 = 5, 16 ÷ 4 = 4.
- Three of the four pairs have a 4 : 1 ratio. 45-9 has a 5 : 1 ratio instead, breaking the shared pattern.
Answer: 45-9
4. Find the odd one out: Eagle, Sparrow, Parrot, Snake
Solution
- Eagle, Sparrow and Parrot are all birds.
- Snake is a reptile, not a bird — it doesn’t share the rule the other three follow.
Answer: Snake
Try these yourself
Find the shared rule first, then check against the answer.
1. Find the odd one out: Triangle, Square, Rectangle, Circle
Answer: Circle (the others are all polygons with straight sides; a circle has none)
2. Find the odd one out: 16, 25, 36, 48
Answer: 48 (the others are perfect squares — 4², 5², 6² — 48 is not)
3. Find the odd one out: 8-64, 5-25, 9-81, 6-42
Answer: 6-42 (the others pair a number with its square; 6² = 36, not 42)
Where this comes up
Classification is a regular topic in the Reasoning/General Intelligence section of every exam Pariksha Saathi covers — SSC CGL, SSC MTS, SSC CHSL, IBPS PO, IBPS Clerk, SBI PO and SBI Clerk.
Practice more Classification questions
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