Fatal errors that require a system reboot occur an average of 7 times per week. (The system runs 24 hours a day, 7 days a week.) The number of fatal errors can be adequately modeled by a Poisson distribution.
a) What is the probability of no fatal errors in a week?
b) What is the probability of 2 fatal errors in 24 hours ?
c) What is the probability of no more than 2 fatal errors in 24 hours?