User:Ahecht/sandbox/quiz2

A customer buys a pair of shoes for $15 and pays with a $20 bill. The cashier does not have change and therefore runs out to the bank next door. The bank teller gives the cashier a $10 bill and two $5 bills. The cashier goes back to the store and gives the customer his shoes and $5 change.

After the customer leaves, the bank teller comes into the store and informs the cashier that the $20 bill was a counterfeit and demands payment from the salesman. The salesman agrees that the $20 bill is worthless and repays the teller with a good $20 bill.

How much money did the shoe store lose in these transactions: