An executive has two routes that she can taketo and from work each day. The first is by interstate; the second requires driving through town. On the average ittakes her 33 minutes to get to work by...

An executive has two routes that she can taketo and from work each day. The first is by interstate; the second requires driving through town. On the average ittakes her 33 minutes to get to work by the interstate and 35 minutes by going through town. The standard deviationsfor the two routes are 6 and 5 minutes, respectively.

Assume the distributions of the times for the two routes are approximately normally distributed.

(a) What is the probability that on a given day, drivingthrough town would be the quicker of her choices?

(b) What is the probability that driving through townfor an entire week (ten trips) would yield a lower average time than taking the interstate for the entireweek?