Question

In a certain state's lottery, 45 balls numbered 1 through 45 are placed in a machine and eight of them are drawn at random. If the eight numbers drawn match the numbers that a player had chosen, the player wins $1,000,000. In this lottery, the order in which the numbers are drawn does not matter.

Compute the probability that you win the million-dollar prize if you purchase a single lottery ticket. Write your answer as a reduced fraction.
P
(win) =

A single lottery ticket costs $2. Compute the Expected Value, to the state, if 10,000 lottery tickets are sold. Round your answer to the nearest dollar.
Answer: $
A single lottery ticket costs $2. Compute the Expected Value, to you, if you purchase 10,000 lottery tickets. Round your answer to the nearest dollar.
Answer: $

Answer 1

Explanation:

The order of the numbers doesn't matter, so we'll use combinations instead of permutations. The number of combinations is:

₄₅C₈ = 215,553,195

So the probability of a ticket having the winning combination is 1 / 215,553,195.

The expected value to the state is:

E(X) = 10,000 (1) ($2) + 10,000 (1 / 215,553,195) (-$1,000,000)

E(X) = $19954

The expected value to you is:

E(X) = 10,000 (1) (-$2) + 10,000 (1 / 215,553,195) ($1,000,000)

E(X) = -$19954