Your dinner bill was $37.90 with 8% tax and 19% tip. What was the final price?
A Tax
B. Tip
C. Final Price

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.