Question

A local high school runs a game at a fundraising event. In this game, marbles are randomly picked froma bag. The bag contains 5 red marbles, 4 blue marbles, and 1 green marble. If a green marble is drawn, you win $10. If the blue marble is drawn, you win $2, and if you draw a red marble you win nothing. The game costs $3 to play. Find the expected value of playing.

Answer 1

Given:

5 red marbles

4 blue marbles

1 green marble

Upon choosing green marble, we win $10

Upon choosing blue marble, we win $2

Upon choosing red marble, we win $0

It costs $3 to play each game.

To find:

The expected value of playing the game

Step by step solution:

Firstly we need to calculate the probablity of occuring of each event:

P (Choosing a red marble) = 5/10 = 1/2

P (Choosing a blue marble) = 4/10 = 2/5

P (Choosing a green marble) = 1/10 = 1/10

We will now associate the money related to each case:

= 1/2 × $0 + 2/5 × $2 + 1/10 × $10

= 0 + $ 4/5 + $1

= $ 1.8