a computer retail store has 11 personal computers instock. a buyer wants to purchase 4 of them. unknown to either theretail store or the buyer, 4 of the computers in stock havedefective hard drives. assume that the computers are selected atrandom.
in how many different ways can the 4 computers be chosen
what is the probability that exactly one of the computers will bedefective
what is the probability that at least one of the computers selectedis defective
