Hello,

(I hope you understood where these formulas came from in e and f)Update:

Can someone confirm these?

a) (1/2)(1/2)^n-1

b) (1/3)(2/3)^n-1

c) E(X)=1/(1/2)=2

d) E(Y)=1/(2/6)=3

e) P(x=y)= sum(n=1 to +oo) 1/6(1/3)^(n-1) = 1/4

f) sum(n=1 to +oo) n*(1/6)*(1/3)^(n-1) = 3/8

The binomial distribution counts the number of successes. The geometric distribution denotes the first time a success happens