Write five pairs of prime numbers less than 20 whose sum is divisible by 5.

Question – Write five pairs of prime numbers less than 20 whose sum is divisible by 5.
(Hint: 3+7 = 10)

Solution –

Five pairs of prime numbers less than 20 whose sum is divisible by 5 are:

2 + 3 = 5 and 5 is divisible by 5.

3 + 7 = 10 and 10 is divisible by 5.

13 + 2 = 15 and 15 is divisible by 5.

7 + 13 = 20 and 20 is divisible by 5.

17 + 3 = 20 and 20 is divisible by 5.

Here, 2, 3, 7, 13 and 17 are prime numbers.

Therefore,  five pairs of prime numbers less than 20  are (2, 3), (3, 7), (13, 2), (13, 7) and (17, 3)  and their sum is also divisible by 5.

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