1.The time t (in minutes) that a customer spends at a check-out counter is believed to follow the exponential distribution. It was observed that 20% of the customers spend more than 3 minutes at the check-out counter.What is the probability that an incoming clerk will spend at most 2 minutes at the check-out counter?

2.The quality control head of a certain manufacturing company has instituted the policy of obtaining 10 samples from the final stage of the production process at the end of each day. If 2 or more items in a sample of 10 are found to be defective, the whole production process is checked.The company operates seven days in a week.During a day's inspection, the 10 items were placed in a box.Two of the items were found to be defective.If 5 items are randomly drawn from the box, what is the probability that the 5 will contain 1 defective?