If p and r are integers, p does not equal 0, and p = -r, which of the following must be true? a) p>r .... b) p+r<0 .... c) p-r<0 .... d) pr<0 Given that p = -r, we can have either p as +ve and r as -ve, or r as +ve and p as -ve. So we cannot conclude that p > r will be true (choice a) or p - r < 0 (choice c) Since p = -r, p+r = 0, so choice b is also not true. Since p and r are of opposite signs, the product pr is always -ve. Hence d is the right option. :)