Question

If m and p are positive integers and (m + p)x m is even, which of the following must be true? Would it be: (A) if m is odd, then p is odd. (B) if m is odd, then p is even. (C) if m is even, then p is even and (D) if m is even, then p is odd. I had chosen D and that was wrong. Would it be C?

Answer 1

for the product to be even, you must have either

m even
or
m+p even

A works, because odd+odd is even
B fails -- odd*odd = odd
C works whether p is even or odd, so it's not true that p must be even.
D the same