Before the football match, the referee asked the captains A and B to choose the attack direction by flipping a coin to guess the pros and cons. If the captain who guesses the head is selected first, c

Before the football match, the referee asked the captains A and B to choose the attack direction by flipping a coin to guess the pros and cons. If the captain who guesses the head is selected first, captain A is the first. There are two possibilities for coins to appear, and there is only one possibility for A to guess the head, so the probability of A choosing first is12.