Malcolm is filling bags with rice. He starts with a 5 1/4 pound container of rice and fills each bag with 5/8 pound of rice. How may bags did Malcolm fill? Help ;-;

Let x have probability generating function gx (s) and let un generating function u(s) of the sequence uo, u1, satisfies p(x > n). show that the (1- s)u(s) = 1 - gx(s), whenever the series defining these generating functions converge.