You are shown into a darkened room and seated in front of a table. You are told that there are 32 coins on the table, 12 are heads up and 20 are tails up. You cannot see anything in the dark. You can touch the coins but you cannot tell which show heads and which show tails. How can you divide the coins into two piles each of which will have an equal number of heads up?
There is no deception in the wording or cheap trick in the solution. The puzzle is as described and it can be solved using a simple mathematical idea.
Taken from this book.
On Amazon.co.uk
On Amazon.com
Stand all the coins on their edge and split into the 2 piles. No heads up on both piles
Stephen, Very creative idea but there is a better solution which solves the problem elegantly.
12 are square, 30 are round
Good try but not right!
Split the coins into two piles: one with 12 coins and the other with 20 coins.
Then turn over all the coins in the pile of 12.
This will always result in the same number of heads-up coins in both piles.
Wow! I admire your logic.