Question

Write five pairs of prime numbers below $20$ whose sum is divisible by $5$?

Answer 1

Finding the pairs of prime numbers below $20$ whose sum is divisible by $5$:

Prime Numbers: The numbers which have only two factors $1$ and the number itself are called Prime Numbers.

For example : $2,3,5,7,11$ etc.

The prime numbers below $20$ are $2,3,5,7,11,13,17,19$.

Therefore, the five pairs of prime numbers below $20$ whose sum is divisible by $5$ are

First pair is $2$ and $3$

$2+3=5$ which is divisible by $5$.

Second pair is $3$ and $7$

$3+7=10$ which is divisible by $5$.

Third pair is $3$ and $17$

$3+17=20$ which is divisible by $5$.

Fourth pair is $2$ and $13$

$2+13=15$ which is divisible by $5$.

Fifth pair is $7$ and $13$

$7+13=20$ which is divisible by $5$.