Chapter 8.2, Problem 3NAEP

A. If c and d are different prime numbers less than 10 and the sum $c+d$ is a composite number greater than 10, what is one possible pair of values for c and d ?

$c=\text{\_}\text{\_}\text{\_},d=\text{\_}\text{\_}\text{\_}\text{\_}$

B. If j and k are different prime numbers less than 10 and the sum $j+k$ is a prime number less than 10, what is one possible pair of values for j and k?

$j=\text{\_}\text{\_}\text{\_},k=\text{\_}\text{\_}\text{\_}\text{\_}$

C. If s and t are different prime numbers greater than 10, explain why the sum $s+t$ cannot be a prime number.