The number of defective circuit boards among those coming out of a soldering machine follows a possion distribution. On a particular 8-hour workday, one defective board is found.
a Find the probability that it was produced during the first hour of operation of that day.
b Find the probability that it was produced during the last hour of operation for that day.
c Given that no defective boards were seen during the first 4 hours of operation, find the probability that the defective board was produced during the fifth hour.