Biased Coin Puzzle

Biased Coin Puzzle

You and your arch rival are competing for the same girl. After years of battling, you both decide to settle it by tossing a coin.

Your rival produces a coin, but you don’t happen to have one on you. You are certain that the coin your rival has produced is loaded, ie. it will come up with heads more than 50% of the time on average.

How do you arrange a fair contest, based purely on chance and not skill, by flipping this coin?

2 Responses

  1. saurabh says:

    1.They need to toss the coin 2 times.
    2. Whoever person makes the call in the first time has to make the second call just opposite…for e.g if he calls head in the first call ,he must call tail in the second turn.

    The reason for this is that the probability of HT AND TH will always be equal.

  2. hey nice suggestion, I was thinking if he knows the coin is loaded to favour heads then he should choose heads all the time hehehe