
probability
in the game of tennis a player has two serves.
if the first serve is succesful the gamae continues.
if the first serve is not succesful the player serves again. if this second service is succesful the game continues.
if both serves are unsuccesful the player has served a "double fault"and loses the point.
Gabriella plays tennis. she is succesful with 60% of her first serves and 95% of her second serves.
calculate the probability that gabriella serves a double fault.

probability
A double fault means that neither her first nor her second serve succeeded. So we need to solve the following:
probability that first serve failed * probability that second serve failed
If her first serve succeeds 60% of the time, it fails the other 40%.
If her second serve succeeds 95% of the time, it fails the other 5%.
So we need to solve for 40% * 5% = 2%.
Steve J