There are twenty-six coins lying on a table in a totally dark room. Ten are heads and sixteen are tails. In the dark, you cannot feel or see if a coin is heads up or tails up.
Your task is to separate the coins into two groups so that each group has the same number of coins heads up as the other group. You may move or flip the coins. How can you accomplish this? No tricks are involved.
Answer
Separate the coins into 2 groups of 10 and 16, then flip over all the coins in the group with 10 coins.
To illustrate, let’s go through an example. In the group of 10, if there are 4 heads, then there would be 6 heads in the group of 16. When you flip all the coins in the group of 10, you will get 6 heads.