38. Three new associateshave been hiredto work atDewey, Cheatham and Howe, a large law office. The rate of success for new associates at the fi rm is 80%. Assumingthat the performanceof each associateis independent of the performance of the others,

draw a three-stageprobability tree anduse it todetermine the probability that

a. only one of the new associates will succeed.

b. at least two associates will succeed.

c. none of the associates will succeed."