Explanation:
2 and 9
3 and 7
4 and 8
what I see right away : the only pair whose sum is a prime number (or only just an uneven number) is 2 and 9.
2 + 9 = 11
3 + 7 = 10
4 + 8 = 12
just because these sums are even numbers they cannot be prime numbers and are "out".
A composite number is a positive integer that can be formed by multiplying two smaller positive integers different than 1.
so, the product of 2 numbers is therefore always a composite number, and the question in that direction is completely redundant (without any additional meaning).
so, again, 2 and 9 is the right answer.