Theory question 105
ProbabilityA building contractor tendered for two independent contracts, X and Y. The probabilities that he will win contract X is 0.5 and not win contract Y is 0.3. What is the probability that he will win: (a) both contracts; (b) exactly one of the contracts; (c) neither of the contracts?
Show the model answer
Model answer
P(X) = 0.5, P(not X) = 0.5, P(Y) = 0.7, P(not Y) = 0.3.
(a) 0.5 × 0.7 = 0.35.
(b) 0.5 × 0.3 + 0.5 × 0.7 = 0.15 + 0.35 = 0.50.
(c) 0.5 × 0.3 = 0.15.
Explanation
For independent events, multiply the probabilities.