SSC Odd One Out (Classification) Questions with Answers

Classification (Odd One Out) is one of the quickest question types in the SSC reasoning section. You are given a group of words, letters or numbers, and you have to find the one that does not belong to the group. One to three questions appear in almost every shift of CGL, CHSL, MTS and GD. This practice paper gives you 30 odd one out questions with answers and explanations, covering words, numbers and letters.

Practice Paper at a Glance

What Is Classification? Basic Concept in Simple Words

In classification, all items but one share a common property (category, type or pattern). The item that does not share the property is the odd one out.

• Word classification: items belong to the same category (fruits, animals, tools), and one belongs to a different category.
• Number classification: numbers follow a common rule (primes, squares, multiples) and one breaks the rule.
• Letter classification: letter groups follow the same pattern (shift of +2, consecutive letters) and one breaks it.

Tricks and Shortcuts for SSC Classification Questions

• Find the common property first by looking at the three most similar items.
• For words, check category, use, habitat, type (living or non-living) and whether the thing is natural or man-made.
• For numbers, test for prime, square, cube, odd or even, multiple of a number and the sum of digits.
• For letters, convert to positions (A = 1 to Z = 26) and compare the gaps within each group.
• For pairs, find the relationship between the two items of each pair (use, sound, product).
• Do not stop at the first similarity: if two options both look odd, find a stronger common property.
• Eliminate items that clearly share the property with others and look at what remains.
• Watch for tricky words: bat is a mammal not a bird, tomato is botanically a fruit but used as a vegetable, and a spider is not an insect.

Set 1: Word Classification (Q1–Q10)

Q1. Find the odd one out: Apple, Banana, Carrot, Mango.
Answer: Carrot
Solution: Apple, banana and mango are fruits. Carrot is a vegetable.

Q2. Find the odd one out: Dog, Cat, Cow, Eagle.
Answer: Eagle
Solution: Dog, cat and cow are mammals (animals). Eagle is a bird.

Q3. Find the odd one out: Table, Chair, Sofa, Hammer.
Answer: Hammer
Solution: Table, chair and sofa are furniture. Hammer is a tool.

Q4. Find the odd one out: Delhi, Mumbai, Kolkata, Ganga.
Answer: Ganga
Solution: Delhi, Mumbai and Kolkata are cities. Ganga is a river.

Q5. Find the odd one out: Rose, Lotus, Jasmine, Mango.
Answer: Mango
Solution: Rose, lotus and jasmine are flowers. Mango is a fruit.

Q6. Find the odd one out: Pen, Pencil, Chalk, Duster.
Answer: Duster
Solution: Pen, pencil and chalk are used for writing. A duster is used for cleaning.

Q7. Find the odd one out: Gold, Silver, Iron, Diamond.
Answer: Diamond
Trick: Gold, silver and iron are metals. Diamond is a non-metal (a form of carbon).

Q8. Find the odd one out: Mercury, Venus, Moon, Mars.
Answer: Moon
Solution: Mercury, Venus and Mars are planets. The Moon is a satellite.

Q9. Find the odd one out: Hindi, Tamil, Kerala, Urdu.
Answer: Kerala
Solution: Hindi, Tamil and Urdu are languages. Kerala is a state.

Q10. Find the odd one out: Sparrow, Crow, Bat, Parrot.
Answer: Bat
Trick: Sparrow, crow and parrot are birds. A bat is a mammal.

Set 2: Number Classification (Q11–Q20)

Q11. Find the odd one out: 2, 3, 5, 9.
Answer: 9
Solution: 2, 3 and 5 are prime numbers. 9 is a composite number.

Q12. Find the odd one out: 4, 9, 16, 24.
Answer: 24
Solution: 4, 9 and 16 are perfect squares. 24 is not.

Q13. Find the odd one out: 11, 13, 17, 21.
Answer: 21
Solution: 11, 13 and 17 are prime numbers. 21 = 3 x 7.

Q14. Find the odd one out: 8, 27, 64, 100.
Answer: 100
Solution: 8, 27 and 64 are perfect cubes. 100 is not.

Q15. Find the odd one out: 12, 18, 24, 35.
Answer: 35
Solution: 12, 18 and 24 are multiples of 6. 35 is not.

Q16. Find the odd one out: 121, 144, 169, 200.
Answer: 200
Solution: 121, 144 and 169 are perfect squares. 200 is not.

Q17. Find the odd one out: 3, 9, 27, 80.
Answer: 80
Solution: 3, 9 and 27 are powers of 3. 80 is not (the next power is 81).

Q18. Find the odd one out: 14, 21, 35, 40.
Answer: 40
Solution: 14, 21 and 35 are multiples of 7. 40 is not.

Q19. Find the odd one out: 31, 37, 41, 51.
Answer: 51
Solution: 31, 37 and 41 are prime numbers. 51 = 3 x 17.

Q20. Find the odd one out: 100, 121, 144, 150.
Answer: 150
Solution: 100, 121 and 144 are perfect squares. 150 is not.

Set 3: Letter, Pair and Mixed Classification (Q21–Q30)

Q21. Find the odd one out: AC, EG, IK, MP.
Answer: MP
Trick: AC, EG and IK have letters with a gap of 2 (A to C, E to G, I to K). In MP, the gap is 3.

Q22. Find the odd one out: BD, FH, JL, OQ.
Answer: OQ
Solution: The first letters go B, F, J and then N (+4 each). OQ should have been NP.

Q23. Find the odd one out: KLM, NOP, QRS, TUW.
Answer: TUW
Solution: The groups are three consecutive letters. TUW should have been TUV.

Q24. Find the odd one out: ABC, DEF, GHI, JKM.
Answer: JKM
Solution: The groups are three consecutive letters. JKM should have been JKL.

Q25. Find the odd one out: CAT, DOG, COW, PEN.
Answer: PEN
Solution: CAT, DOG and COW are animals. PEN is not.

Q26. Find the odd one out: 3C, 4D, 5E, 6G.
Answer: 6G
Trick: Each number is paired with the letter at that position in the alphabet (3 = C, 4 = D, 5 = E and 6 = F). So 6G does not fit.

Q27. Find the odd one out: (2, 4, 8), (3, 9, 27), (4, 16, 64), (5, 10, 15).
Answer: (5, 10, 15)
Solution: The first three are x, x^2, x^3. The last group does not follow this pattern.

Q28. Find the odd one out: Lion - Roar, Dog - Bark, Cat - Meow, Cow - Milk.
Answer: Cow - Milk
Solution: The others are animals with their sounds. Milk is a product, not a sound.

Q29. Find the odd one out: 3-4-5, 5-12-13, 8-15-17, 6-7-8.
Answer: 6-7-8
Solution: The first three are Pythagorean triples. 6, 7 and 8 do not satisfy a^2 + b^2 = c^2.

Q30. Find the odd one out: Triangle, Square, Circle, Cube.
Answer: Cube
Solution: Triangle, square and circle are 2D shapes. A cube is a 3D solid.

Common Mistakes in Classification Questions

• Choosing an option because it looks different without finding a clear common property.
• Missing a second common rule (for example, both prime and odd) and picking the wrong answer.
• Treating a bat as a bird, a spider as an insect or a tomato as only a vegetable.
• Not checking the letter positions in letter groups.
• Spending too long on one question instead of moving on.
• Ignoring the difference between living and non-living, natural and man-made.

How to Practice These 30 Questions

1. Spend about 20 seconds per question.
2. Always write the common property of the group in your rough work.
3. Solve each set in 6 minutes.
4. Review the explanation of each wrong answer.
5. Revise squares, cubes and primes before solving number sets.

Related Topics to Study Next

• Analogy Questions
• Number Series Questions
• Venn Diagram Questions
• SSC Previous Year Papers

Frequently Asked Questions

What is classification in reasoning?

Classification (odd one out) means finding the item that does not belong to a group where all the other items share a common property.

How many classification questions come in SSC exams?

Generally one to three classification questions appear in the reasoning section of SSC CGL, CHSL, MTS and GD.

What are the types of classification questions?

The types are word classification, number classification, letter classification and sometimes pair or figure classification.

How do I solve number classification questions?

Check whether the numbers are prime, squares, cubes, multiples of a number or follow some digit-sum property. The number that breaks the property is the answer.

How do I solve letter classification questions?

Convert the letters to their positions and compare the gaps within each group. The group with a different pattern is the odd one out.

What if two options seem to be odd?

Find a stronger common property that covers all but one option. If still unclear, look at the more specific common property among the other three.

Are bats birds?

No. Bats are mammals, so in a group of birds, a bat is the odd one out.

Is classification the same as analogy?

No. In analogy you find the relationship between two items and apply it to another pair. In classification, you find the item that does not match the others.

How can I improve in classification questions?

Build general knowledge of categories (animals, plants, metals, shapes, countries), practise one set daily and revise number properties.

How should I prepare classification for SSC exams?

Practise a mix of word, number and letter classification, learn the common categories and review your mistakes regularly.