Question
a direct sale company started out with two members in the first generation. each member has to recruit another two new members him or her. find the minimum number of generations such that the total number of members exceeds 1200
(hint: geometric series)
(hint: geometric series)
Answers
oobleck
look at the sequence:
2
2+4=6
6+12 = 18
so this is a GP with a=2, r=3
2(3^n - 1)/(3-1) > 200
3^n > 201
n > 4.8
so, 5 generations
2
2+4=6
6+12 = 18
so this is a GP with a=2, r=3
2(3^n - 1)/(3-1) > 200
3^n > 201
n > 4.8
so, 5 generations