A survey was conducted to measure the number of hours students between the ages of 15 and 18 spend on the phone. The number of hours was normally distributed with a mean of 8 hoursand a standard deviation of 2.5 hours.

a. Find the probability that a studentbetween the ages of 15 and 18 spend more than 5 hours on the phone.

b. Find the probability that a student between the ages of 15 and 18 spends less than 1 hour on the phone