February 4, 2014
Problem of the Week
for Tuesday, February 4, 2014
Your Uncle Pascal has returned from his trip to Timbuktu and has brought you a pair of kid gloves and a black scarf. He puts twenty gold coins on the table- 14 of which are face down and 6 of which are face up. "If you can separate these coins into two piles that have the same number of face-up coins in each, you win all twenty coins." Just before you start, your uncle ties the black scarf around your eyes. "But you must do it blind-folded. And you must put on those gloves as well. No fair feeling the difference in your fingers between the face-up and face-down coins. But I will allow you to turn over any coins you wish before you are done." What strategy can you use to guarantee that can separate the coins into two piles that contains the same number of coins that are face-up?