Question

Which of the following is not co-prime?

$8,10$

Answer 1

Checking whether the numbers are co-prime or not:

Two numbers are co-prime if they have common factor as $1$ only

Factors of $8=1,2,4,8$

Factors of $10=1,2,5,10$

Common factors of $8,10$ are $1,2$

Hence, $8,10$ is not co-prime