Question

Suppose two $20 bills, three $10 bills, one $5 bill, and seven $1 bills are placed in a bag. If you were to pull a bill at random, what is the expected value for the amount chosen

Answer 1

Assuming that the $1 bill was pulled at random, then the expected value of the amount chosen is
`(7)/(13)`.

Explanation:

From the given question, the bag contains;

$1 bill = 7

$5 bill = 1

$10 bill = 3

$20 bill = 2

Total number of bills in the bag = 13

Pulling a bill at random, the bills would have an expected value as follows:

For $1 bill, the expected value =
`(7)/(13)`

For $5 bill, expected value =
`(1)/(13)`

For $10 bill, expected value =
`(3)/(13)`

For $20 bill, the expected value =
`(2)/(13)`

Assuming that the $1 bill was pulled at random, then the expected value of the amount chosen is
`(7)/(13)`.