ESP Again Suppose a friend says he can predict whether a coi

ESP Again Suppose a friend says he can predict whether a coin flip will result in heads or tails. You test him, and he gets 20 right out of 20. Do you think he can predict the coin flip (or has a way of cheating)? Or could this just be something that is likely to occur by chance? Explain without performing any calculations.

Solution

It is likely to occur by chance if the coin is unbiased.

If the coin is biased then it is a cheating.

Thus the result is based on the coin.