Exams › IBPS PO › Quantitative Aptitude

Which one of the following is not a prime number?

1. 31
2. 61
3. 71
4. 91

Correct answer: 91

Solution

31, 61, and 71 are prime numbers. But 91 = 7 × 13, so it has factors other than 1 and itself and is not prime.

Related IBPS PO Quantitative Aptitude questions

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