Question

The mathematics club of RAD Senior High School organized a raffle where the prize is the latest edition of a certain brand of the calculator. the raffle aims to raise funds for their club. they were able to sell 1000 tickets that cost 5 pesos each. if they spent 3500 on the prize, what will be the expected gain of a student who will buy one ticket?

Answer 1

E(X)=$\sum{ }$X$\times$P(X)

There's a probability of 1/1000 to win 3500 pesos and 999/1000 to loose 5 pesos

E(X) = $\sum$ (3500$\times\frac{1}{1000}+(-5)\times\frac{999}{1000}$) = -1.495