SOLUTION: Tom and Mary agree to meet at some place at a certain time. The probability that Tom keeps his appointment is 0.7, and that either of them keeps the appointment is 0.9. Given tha

Algebra ->  Probability-and-statistics -> SOLUTION: Tom and Mary agree to meet at some place at a certain time. The probability that Tom keeps his appointment is 0.7, and that either of them keeps the appointment is 0.9. Given tha      Log On


   

Question 1159302: Tom and Mary agree to meet at some place at a certain time. The probability that Tom
keeps his appointment is 0.7, and that either of them keeps the appointment is 0.9. Given
that Tom did not keep the appointment, what is the probability that Mary did not either?
Answer by VFBundy(438) About Me  (Show Source):
You can put this solution on YOUR website!
P(Tom + Mary both do not keep app't)/P(Tom does not keep app't) = 0.1%2F0.3 = 0.3333