Practice Questions
Concept Explanation
Odd-one-out questions here stress patterns and rules: numbers, letters, digit properties, or short codes. Three options follow the same rule; one breaks it. Unlike pure classification by topic (animals, capitals), you first find the rule, then eliminate the misfit.
Pattern types you will see
- Number rules: squares, cubes, primes, AP/GP, digit sums
- Letter rules: alphabet position, +2 skips, mirror pairs (A–Z), reverse pairs
- Mixed codes: 2Z, J10, 4E style (number + letter linked by a formula)
How to solve fast
- Write the rule for option A in one line (e.g. “perfect cube”, “+4 each time”).
- Test B and C with the same rule.
- The option that fails is the answer; do not rely on meaning alone.
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Q1 EasyAll options are perfect cubes except one. Which is the odd one out?Explanation8, 27, and 64 are 2³, 3³, and 4³; 100 is not a perfect cube.
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Q2 EasyEach option is an even number except one. Which is the odd one out?Explanation21 is odd; the others are even.
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Q3 EasyEach option is a multiple of 7 except one. Which is the odd one out?Explanation32 is not divisible by 7; the others are.
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Q4 EasyEach option is a perfect square except one. Which is the odd one out?Explanation38 is not a square; 16, 25, and 36 are squares.
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Q5 EasyEach word has exactly three letters except one. Which is the odd one out?ExplanationTrain has five letters; the others have three.
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Q6 EasyEach number is in the 5, 10, 15, … series except one. Which is the odd one out?Explanation19 is not a multiple of 5; 5, 10, and 15 are.
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Q7 EasyEach option is a prime number except one. Which is the odd one out?Explanation21 is composite; the others are prime.
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Q8 EasyEach option is a palindrome except one. Which is the odd one out?ExplanationTable does not read the same forwards and backwards.
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Q9 EasyEach number is a power of 2 except one. Which is the odd one out?Explanation12 is not a power of 2; 2, 4, and 8 are.
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Q10 EasyEach option uses only vowels except one. Which is the odd one out?ExplanationBC has no vowels; the others do.
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Q11 EasyEach option has digits in strictly increasing order except one. Which is the odd one out?Explanation852 decreases; the others increase left to right.
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Q12 EasyEach option is a multiple of 3 except one. Which is the odd one out?Explanation17 is not divisible by 3; the others are.
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Q13 EasyEach word starts and ends with the same letter except one. Which is the odd one out?ExplanationOpen starts with o and ends with n; the others match first and last letters.
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Q14 EasyEach number is the sum of the two before it in a Fibonacci-style list starting 1, 1, 2, 3, 5, 8 except one. Which is the odd one out?Explanation10 is not a Fibonacci number; 3, 5, and 8 are.
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Q15 EasyEach option has all consonants except one. Which is the odd one out?ExplanationAE contains vowels; the others are consonant-only groups.
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Q16 EasyEach number increases by 4 (3, 7, 11, 15, …). Which is the odd one out?Explanation14 breaks the +4 chain after 11 (should be 15).
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Q17 EasyEach option matches (position)(letter at that position): 1A, 2B, 3C, … Which breaks it?Explanation4th letter is D, so it should be 4D, not 4E.
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Q18 EasyEach pair steps back two letters (ZX, VU, TS, RQ, …). Which breaks the pattern?ExplanationEach letter drops by 2; after TS the next pair is RQ, not WR.
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Q19 EasyEach option is a three-letter animal name except one. Which is the odd one out?ExplanationBear has four letters; the others have three.
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Q20 EasyEach option is n² for n = 4, 5, 6, 7 except one. Which is the odd one out?Explanation48 is not a square; 16, 25, and 36 are 4², 5², 6².
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Q21 EasyEach option doubles the previous starting at 3 (3, 6, 12, 24, …). Which is the odd one out?Explanation18 is not in the doubling chain from 3; next after 12 is 24.
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Q22 EasyEach option is a consonant cluster of length 3 except one. Which is the odd one out?ExplanationIOU is vowels only; the others are three consonants.
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Q23 EasyEach option is a month with 30 days except one. Which is the odd one out?ExplanationJanuary has 31 days; April, June, and September have 30.
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Q24 EasyEach option is a perfect cube except one. Which is the odd one out?Explanation30 is not a cube; 1, 8, and 27 are 1³, 2³, and 3³.
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Q25 MediumEach pair mirrors the alphabet (A with Z, B with Y, …). Which pair breaks the pattern?ExplanationD should pair with W; DY does not follow the mirror rule.
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Q26 MediumEach option matches letter + position (A1, B2, C3, …). Which breaks the pattern?ExplanationJ is the 10th letter, so the form should be J10, not J9.
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Q27 MediumConsecutive letter pairs skip one letter (AB, CD, EF, …). Which pair breaks the pattern?ExplanationAfter EF the next pair should be GH; EH is wrong.
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Q28 MediumEach number is a product of two consecutive integers (2, 6, 12, 20, …) except one. Which is the odd one out?Explanation22 is not of the form n(n+1); 6=2×3, 12=3×4, 20=4×5.
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Q29 MediumEach option is a Fibonacci number except one. Which is the odd one out?Explanation6 is not in the Fibonacci sequence 1, 1, 2, 3, 5, 8; 1, 2, 3 appear in it.
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Q30 MediumEach option is one more than a square (5, 10, 17, 26, …) except one. Which is the odd one out?Explanation5=2²+1, 10=3²+1, 17=4²+1; 20 is not one more than a perfect square.
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Q31 MediumEach option is a cube of an even integer except one. Which is the odd one out?Explanation125 = 5³ (odd base); the others are cubes of 2, 4, and 6.
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Q32 MediumEach option is a letter followed by its reverse position from Z (A=Z, B=Y, …). Which breaks it?ExplanationB should pair with Y, not W.
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Q33 MediumEach option is a triangular number (1, 3, 6, 10, …) except one. Which is the odd one out?Explanation11 is not triangular; 3, 6, and 10 are.
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Q34 MediumEach option has digit-sum 9 except one. Which is the odd one out?Explanation4+4=8; the others sum to 9.
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Q35 MediumEach option follows 2n−1 for n = 2,3,4,5 except one. Which is the odd one out?Explanation8 is even; 3, 5, and 7 are odd terms 2n−1.
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Q36 MediumEach pair is two letters two apart (AC, CE, EG, GI, …). Which breaks the pattern?ExplanationAfter EG comes GI (G and I); EJ does not continue the chain.
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Q37 HardEach option is even number + letter falling by 2 from Z (2Z, 4X, 6V, …). Which breaks the pattern?ExplanationAfter 6V the next should be 8T (8 and T); 8U breaks the letter step.
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Q38 HardEach triple has letters in AP with gap 2 (ACE, BDF, CEG, …). Which breaks the chain when each group shifts by +1?ExplanationAfter CEG the +1 shift on each letter gives DFI, not EGI.
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Q39 HardEach option follows (odd number)(letter two steps back in alphabet): 3Y, 5W, 7U, … Which breaks it?Explanation9 should pair with S (9S); 9T breaks the letter step.
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Q40 HardEach option is a Roman numeral for 5, 10, 15, 20 except one. Which is the odd one out?ExplanationV=5, X=10, XV=15; XXV is 25, not the next step of 20 in the +5 list (XX).