Question

Word of mouth advertising can be an effective form of marketing , or it can be very harmful. Consider a new restaurant that serves 27 customers on its opening night.

A) Of the 27 customers , 25 found the experience enjoyable and each told 3 friends over the next month. This group each told 3 friends over the next month , and so on, for six months. Assuming that no one heard twice, how many people have had a positive experience or heard positive reviews of the restaurant?

B) Suppose the 3 unhappy customers each told 6 friends over the next month about the experience. This group then each told 6 friends, and so on, for six months. Assuming that no one heard twice, how many people have had a negative experience or heard a negative review.

Answer 1

First question: Of the 27 customers, how can there be 25 happy and 3 unhappy?

in any case, just some the geometric progression, using the ratio r=3 or 6, as appropriate.