1. On the average, 5% of T-shirts made by an automatic sewing machine are defective. During 1-hour operation, the machines make twenty T-shirts.
a. Find the probability if more than two T-shirts are found defective in 1-hour operation.
b. What is the probability that the seventh T-shirt made is the fourth found to be defective in 1-hour operation?
c. The factory operates 15 automatic sewing machines. When more than two T-shirts are found to be defective in 1-hour of a machine’s operation, the machine is shut-down for repair. What is the probability that two machines will be shut-down in 1-hour operation?