Need help with understanding binomial & geometric probability problems.

Multiple Choice. 4. Sixty-five percent of all divorce cases cite incompatibility as the underlying reason. If four couples file for a divorce, what is the probability that exactly two will state incompatibility as the reason? (a) .104 ( b ) 207 (c) .254 (d) .311 (e) .423 5. Binomial and geometric probability situations share many conditions. Identify the option that is not shared. a) The probability of success on each trial is the same. (b) There are only two outcomes on each trial. (c) The focus of the problem is the number of successes in a given number of trials. (d) The probability of a success equals 1 minus the probability of a failure. (e) The mean depends on the probability of a success. 6. An inspection procedure at a manufacturing plant involves picking thirty items at random and then accepting the whole lot if at least twenty-five of the thirty items are in perfect condition. If in reality 85% of the whole lot is perfect, what is the probability that the lot will be accepted? (a) .524 ( b ) . 667 (c) .186 (d) .476 (e).711 7. A recent study of the WA Upper School student body determined that 41% of the students were "chic". If Mr. Floyd has developed a test for "chic-ness", what is the average number of students we would need to test in order to find one who is "chic"? (a) 2 (b) 2.43 (c) 3 (d) 3.57 (e) 1, because the study is clearly in error since all WA students are "chic"