Question

a drawer has ten blue, ten white, and ten red socks. without looking at them you pull some socks out. what is the least number of socks you need to pull to ensure you get two pairs of matching socks? justify your answer.

Answer 1

The answer is 7 socks.

Explanation:

To ensure one matching pair, you need to pull out 4 socks. If none of the first three match, the fourth one will guarantee a matching pair.

You will then need to pull out 3 more socks, for a total of 7 socks, to ensure two matching pairs.