A survey indicated that 65% of the families in an an~a have cars. Find, correct to three decimal places, the probability that among 7 families selected at random in the area.
(a) exactly 5;
(b) 3 or 4;
(c) at most 2 of them have cars.
Through a few candidates attempted this question, the few who did performed well. They were able to substitute the values of p(.65) and q(.35) into the binomial expansion and obtained correct answers.
