CA Foundation · Quantitative Aptitude · Number Series, Coding-Decoding and Odd Man Out
Find the odd one out: 3, 5, 11, 17, 21, 29.
The odd one out is 21. All the other numbers, 3, 5, 11, 17 and 29, are prime, whereas 21 is divisible by 3 and 7 and is therefore a composite number.
- A5
- B17
- C21Correct
- D29
Explanation
3, 5, 11, 17 and 29 are prime numbers. 21 = 3×7 is composite, so it does not share the property.
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