Brain Teaser - How Many socks?

In your drawer, there are six white socks, eight black socks, four green socks and two brown socks. Without looking at the socks, how many do you have to reach in and pull out to end up with a matching pair?

Answer
You need to take out five socks. There are four colours of socks, so if you take out five, you are sure to have two of the same colour.