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?

He must pull out a minimum of ???? socks.

If there are four colours of socks (as in this case).

If I pull out 5 socks, can you tell me if it is possible NOT to have a pair of the same colour?

To determine the minimum number of socks Matt must pull out, let's consider the worst-case scenario. In this case, he would pick socks of different colors until he has one of each color.

In the worst-case scenario:
- Matt picks a black sock. The number of black socks remaining is 21.
- Matt picks a white sock. The number of white socks remaining is 21.
- Matt picks a blue sock. The number of blue socks remaining is 21.
- Matt picks a brown sock. The number of brown socks remaining is 21.

At this point, Matt has one sock of each color, but he still doesn't have a matching pair. Therefore, Matt needs to pick one more sock to guarantee that he has a matching pair.

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