An average of four trucks per hour arrive at the receiving dock at Yuri Industries. No trucks have arrived in the last half-hour. Assuming that all Poisson conditions are met, determine the probability that you will need to wait
a. At least 45 more minutes before the next truck arrives.
b. Less than 10 more minutes before the next truck arrives.
c. Between 15 and 30 more minutes before the next truck arrives.