Please answer question ii. This is a study prep question. For a computer science course.

(25 points) Let X be a. set with n 2 1 elements. For 0 5 k S 11, let f(k,n) denote the number of subsets of X with 1: elements. (it) Let Pn(s:) = 2:0 f(k,n)e:'\". Using (L) prove that (1+ me) = Pane)