Question

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

Answer 1

Answer:

The pairs of numbers are (7, 13) and (13, 17) and (19, 11)

Solution:

Given that we have to write three pairs of prime numbers less than 20 whose sum is divisible by 5

Let us first list the prime numbers less than 20

A prime number is a whole number greater than 1 whose only factors are 1 and itself

Prime numbers less than 20 are: 2, 3, 57111317 19

We have to find pairs of prime numbers in above list whose sum is divisible by 5 Number that are divisible by 5 must end in 5

or 0

7+ 13 = 20 = divisible by 5

13+ 17 = 20 = divisible by 5

19 + 11 = 30 = divisible by 5

Thus the pairs of numbers are (7, 13) and

(13, 17) and (19, 11)