SOLUTION: Let A and B be two events. Suppose Pr[A]=0.4, Pr[B]=0.5 and Pr[the intersection of events A and B]=0.1. Find the probability that A or B occurs, but not both

Algebra ->  Probability-and-statistics -> SOLUTION: Let A and B be two events. Suppose Pr[A]=0.4, Pr[B]=0.5 and Pr[the intersection of events A and B]=0.1. Find the probability that A or B occurs, but not both       Log On


   

Question 1038184: Let A and B be two events. Suppose Pr[A]=0.4, Pr[B]=0.5 and Pr[the intersection of events A and B]=0.1. Find the probability that A or B occurs, but not both
Answer by richard1234(7193) About Me  (Show Source):
You can put this solution on YOUR website!
Pr(A or B) = Pr(A) + Pr(B) - Pr(A and B) = 0.4 + 0.5 - 0.1 = 0.8

However this includes the case where both A and B occur. To account for this, we have to subtract 0.1 again.

Pr(A xor B) = 0.8 - 0.1 = 0.7

So the probability that A or B occurs, but not both, is 0.7.