A drawer contains 22 black socks, 22 white socks, 22 blue socks, and 22 brown socks. If the light is off and Matt reaches into the drawer to get his socks, what is the minimum number of socks he must pull out in order to be sure that he has a matching pair?

since there are only 4 colors, 5 socks must include a match

Nope, Steve, one could pull out 5 blue.

the minimum number to get a match with 100 percent absolute certainty is 23.

Dang. Gotta read more carefully.

To find the minimum number of socks Matt must pull out to be sure that he has a matching pair, we need to consider the worst-case scenario. That would be if Matt picks socks of different colors each time he reaches into the drawer.

In this situation, Matt can pick at most 4 socks of different colors (1 black, 1 white, 1 blue, and 1 brown) without getting a matching pair. The fifth sock he picks, regardless of its color, will guarantee that he has a matching pair.

Therefore, the minimum number of socks Matt must pull out in order to be sure that he has a matching pair is 5.