A box has 8 pens. Four are blue, one is green, and three are red.Three pens are drawn without replacement.

a.What is the probability of getting three of the same color?

If three pens aren't the same color, then the pens are put back and the procedure (drawing three pens and replacing if not all the same) is repeated until three of the same color are obtained.

b.How many times do you expect to perform this procedure until you get three of the same color?

c.What is the probability that three of the same color will be obtained the sixth time the procedure is performed?