Simon has decided to improve the quality of the products he sells. Now only one out of five CDs selected from the bins is defective (i. e., the probability that a diskette is bad is only 0.2). If three CDs are chosen at random, what is the probability :
(a)that all three CDs are good?
(b)that all three CDs are bad?
(c)that [exactly] one of the three CDs is bad?
(d)that there are more good CDs than bad ones?