Question

Dana and Cathy are playing tennis. The probability that Dana wins at least one out of two games is 0.3. What is the probability that Dana wins at least one out of four

Answer 1

51%.

Explanation:

If we have that the probability when at least one wins is 0.3, it means that the probability that none wins would be:

1 - 0.3 = 0.7 would be the probability of not winning any of the first two games, how are two games and are independent events, the probability of not winning any of the 4 games would be:

(0.7) * (0.7) = 0.49

Therefore, the probability of winning at least one game, would be the complement of not winning any, that is:

1 - 0.49 = 0.51

Which means that the probability of winning at least 1 of the four game is 51%.