Factory received a shipment of 23 hammers, and the vendor who sold the items knows there are 8 hammers in the shipment that are defective. Before the receiving foreman accepts the delivery, he samples the shipment, and if too many of the hammers in the sample are defective, he will refuse the shipment. For each of the following, give your responses as reduced fractions. If a sample of 8 hammers is selected, find the probability that all in the sample are defective. If a sample of 8 hammers is selected, find the probability that none in the sample are defective.