The probability of Steve serving up an ace in tennis is 015

The probability of Steve serving up an ace in tennis is 0.15, and the probability that he double faults is 0.25. What is the probability that Steve does not serve an ace or a double fault? (a) 0.5 (b) 0.15 (c) 0.25 (d) 0.4 (e) 0.9 (f) 0.6 (g) None of the above.

Solution

PROBABILITY OF SERVE TENNIS = 0.15

PROBABILITY OF NO ACE = 1-0.15 = 0.85

PROBABILITY OF DOUBLE FAULT = 0.25

PROBABILITY OF NO DOUBLE FAULT = 1-0.25 = 0.75

NOW THE PROBABILITY OF NOT SERVING ACE OR DOUBLE FAULT = 0.75*0.85 = 0.6 HENCE OPTION F IS THE ANSWER