Socks in the Drawer

You have a drawer with 10 pairs of black socks and 10 pairs of white socks. How many times do you need to blindly reach inside the drawer and take out a sock, so that you get a matching pair?

Only 3 times. Once you have two socks of the same color, they already form a matching pair.

Cow and Rope

A cow is tied to a 4 meter long rope. There is food, 20 meters away from the cow. However, the cow manages to go to the food and eat it. How come?

The rope is not tied to anything but the cow, so the cow is free to go to the food.