7. The J.O. Supplies Company buys calculators from a Korean supplier. The probability of a defective calculator is 25%. If 16 calculators are selected at random, what is the probability that less than 4 of the calculators will be defective?

8. An important part of the customer service responsibilities of a cable company relates to the speed with which trouble in service can be repaired. Historically, the data show that the likelihood is 0.45 that troubles in a residential service can be repaired on the same day. For the first 8 troubles reported on a given day, what is the probability that more than 3 troubles will be repaired on the same day?