Suppose that in an assortment of16calculators there are4with defective switches. Draw with and without replacement. (Enter the probabilities as fractions.)

(a) If one machine is selected at random, what is the probability it has a defective switch?

with replacement

without replacement

(b) If two machines are selected at random, what is the probability that both have defective switches?

with replacement

without replacement

(c) If three machines are selected at random, what is the probability that all three have defective switches?

with replacement

without replacement