Question

Which one of the following groups of numbers includes all prime numbers? A. 7, 17, 63, 67 B. 3, 11, 23, 31 C. 1, 3, 11, 23 D. 2, 3, 5, 15

Answer 1

The prime number is a natural number greater than 1 that has no positive divisors other than 1 and itself.

A.
7 - is a prime number
17 - is a prime number
63 - is not a prime number because 63 = 3 × 21

B.
3 - is a prime number
11 - is a prime number
23 - is a prime number
31 - is a prime number

C.
1 - is not a prime number

D.
2 - is a prime number
3 - is a prime number
5 - is a prime number
15 - is not a prime number because 15 = 3 × 5