The local health board operates a fleet of cars. Based on past information, for the cars used, the distance traveled by a car in a day averages 170 km with a standard deviation of 40 km. Assuming a normal distribution of distances:
(a) What proportion of cars used in any day travel less than 100 km?
(b) What daily distance would be traveled by the 10% of cars that travel the greatest distance?
(c) A car is booked out for 5 days. What is the probability that the total distance traveled is more than 1100 km?