The probability that a construction company wins a particula

The probability that a construction company wins a particular contract is 50%. The probability that it wins a second contract is 20%. The probability that it wins both contracts is 10%. What is the probability that it wins neither contract? Use a Venn Diagram and/or the addition rule to help determine your answer.

5%

10%

25%

40%

90%

Solution

A- wins a particular contract = 0.5

B - wins a second contract = 0.2

AB - wins both

P(A) = 0.5

P(B) = 0.2

P(AB) = 0.1

P(AUB) = 0.5+0.2-0.1 = 0.6

P(AUB)\' = 1-0.6 = 0.4

Hence answer is 0,4

= 40%