The scheduled time for a flight between Kuwait city and the city of Dubai in the United Arab Emirates is 75 minutes. Assume that the actual flight time is uniformly distributed between 73 and 85 minutes. Find the probability that the flight time will be

a. less than 78 minutes.

b. between 75 and 80 minutes.

c. greater than 65 minutes.

d. Calculate the mean and standard deviation of the flight time between the two cities.