ESRF (European Synchrotron Radiation Facility) reports that its X-ray equipment has an average failure rate of .02 failures per hour. Assume all Poisson conditions are met. Use the Poisson probability function to determine the probability of
a. Exactly one failure in a 10-hour period.
b. No more than one failure in a 120-hour period.
c. Exactly three failures in a 100-hour period.
d. No failures in 30-hour period.