Question

write three pairs of prime numbers less than 20 whose sum is divisible by 5?​

Answer 1

Answer:

(5,5), (3,17), (7,13)

Answer 2

Answer:

Let's express these numbers as a sum of two prime numbers lesser than 20, that are, 2, 3, 5, 7, 11, 13, 17, 19

a) 5 = 2 + 3

b) 10 = 3 + 7

c) 15 = 2 + 13

d) 20 = 3 + 17

e) 20 = 7 + 13

Therefore, five pairs of Prime Numbers less than 20 whose sum is divisible by 5 are (2,3), (3,7), (2,13), (5,5), (3,17), (7,13)