Which of the following numbers are prime? (a) 23 (b) 51 (c) 37 (d) 26

Question – Which of the following numbers are prime? (a) 23 (b) 51 (c) 37 (d) 26

Solution – 

Prime numbers : Prime numbers are the numbers with exactly two factors i.e., 1 and itself.

Composite numbers : Composite numbers  has more than two factors

(a) 23 is a prime number.

23 has exactly 2 factors i.e., 1 and 23.

(b) 51 is a composite number .

51 = 1 × 3 × 17

Hence, 51 has more than two factors i.e., 1, 3, 17 and 51.

(c) 37 is a prime number.

37 has exactly 2 factors i.e., 1 and 37.

(d) 26 is a composite number.

26 = 1 × 2 × 13

Hence, 26 has more than two factors i.e., 1, 2, 13 and 26

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