Blog # 46 : Find out the matching sock

Fint out the matching socks: Michael have ten pairs of black socks, eight pairs of white socks and seven pairs of green socks. Everything is mixed in a draw. As there is no light he were not able to identify the color of the socks. How many of the socks did he want to take to match one pair ? p.s. - For Remarks please hit the question name once, given in the question itself. For Hint, hit it twice and for the solution, hit it thrice. Remarks: There is no difference between left and right socks. Hints: The principle used is the Pigeon Hole Principle. Try to learn more about it from Wikipedia, since many clever solutions result from clever application of the principle. Solution: The answer is 4 since in worst case all 3 socks taken first will be different color then the 4th one would be repetition. However if we consider a left sock to be different from right one, then at least 10 + 8 + 7 + 1 = 26 socks are needed.