This question is usually asked to check the candidate's intellectual ability. The answer to the question is very simple. Here's how ill you get the right answer -  "In this, there will be three scenarios:  If the first pair of socks are red, and the next one you draw is red, then you have a match. If not, you'll have to draw again.   If the second socks are yellow, then the third socks drawn are red or yellow, you have a match. If not, draw again.  If the third sock is green, then the next socks you draw would be a perfect pair for all the socks.