A research team conducted a study showing that approximately 20% of all businessmen who wear ties wear them

so tightly that they actually reduce blood flow to the brain, diminishing cerebral functions. At a board meeting of

15 businessmen, all of whom wear ties, what are the following probabilities? (Round your answers to three decimal

places.)

(a) at least one tie is too tight

.965

(b) more than two ties are too tight

? - cannot figure this answer out

(c) no tie is too tight

.035

(d) at least 13 ties are not too tight

0.398