Question

If least prime factor of p is 3 and least prime factor of q is 5 , then what is least prime factor of (p+q)?

Answer 1

We conclude 2 isn't a factor of p or q (since their least factors are 3 and 5 respectively), i.e. p & q are both odd. So the sum is even and its least prime factor must be the smallest prime, 2.

Answer: 2