Question

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

Answer 1

Five pairs of prime numbers less than 20 whose sum is divisible by 5 are (2,3), (2,13), (3,17), (11,3) and (7,3).

Step-by-step explanation:

We have to find five pairs of prime numbers less than 20 whose sum is divisible by 5.​

Firstly, as we know that prime numbers are those numbers which come in their own table and they have only two factors: 1 and the number itself.

So, the prime numbers less than 20 are given as;

2, 3, 5, 7, 11, 13, 17, 19

Now, we will try to make pairs of prime numbers whose sum is divisible by 5;

(2 , 3) = 2 + 3 = 5

(2 , 13) = 2 + 13 = 15

(3 , 17) = 3 + 17 = 20

(11 , 3) = 11 + 3 = 15

(7 , 3) = 7 + 3 = 10

So, these are the pairs of prime numbers whose sum is divisible by 5.