Steve has 25 socks. He has 4 pairs of socks that match, and all the others don't match. How many mismatching socks does Steve have altogether? Think carefully first, then make a decision:
In each pair of socks there are 2 / 1 = 2 socks. Steve has 2 * 4 = 8 matching socks. Steve has 25 - 8 = 17 mismatching socks. So, the answer is 17.