A female moth lays nearly 150 eggs. In on year there may live up to five generations. Each larva eats about 20mg of wool. Assume that 2/3 of the eggs die and that 50% of the remaining moths are females. Estimate the amount of wool that may be destroyed b the descendants of one female within a year. (The first female belongs to the first generation)
assume that each female produces n live children, of whom f are females.
Then generation 1 has 1 female
(no idea whether there are any males in generaton 1. presumably at least 1, but hey...)
generation 2 has 1 + n
of whom f are females
generation 3 has the original 1 pus her n kids, plus offspring
1+n + f(1+n) = (1+n)(1+f)
and so on