A large chain retailer purchases a certain kind of electronic device from a manufacture.The manufacture indicates that the defective rate of the device is 3%.

i. The inspector randomly pics 20 items from a shipment .What is the probability that there will be at least one defective item among these 20?

ii. Suppose that a retailer receives 10 shipments in a month and inspector randomly test 20 devices per shipment.What is the probability that there will be exactly 3 shipments each containing at least one defective device among the 20 that are selected and tested from the shipment.