You are blindfolded and 10 coins are place in front of you on table. 5 are having their heads-side up and 5 are having their tails-side facing upward.
You cannot tell which way they are by touching the coin.
You are allowed to touch the coins and flip them as many times as you want.
How do you make two piles of coins each with the same number of heads-up and tails-up?