Question 1168144
the probability of taking the train is the sum of the probability of taking the train given that it is a dry day plus the probability of taking the train given that it is a wet dry.


the probability that it is a dry day is 5/6 and the probability that it is a wet day is 1/6.


the probability of taking the train given that it is a dry day is 1/2.


the probability of taking the train given that it is a wet day is 11/15.


the probability of taking the train is therefore 5/6 * 1/2 + 1/6 * 11/15 = 5/12 + 11/90 = 75/180 + 22/180 = 97/180 = .5389