Question

A cashier’s drawer has some $5 bills, some $10 bills, and some $20 bills. There are 15 bills worth a total of $185. How many $5 bills, $10 bills, and $20 bills are there?

Answer 1

4 * $20 , 10* $10 and 1 * $5 bills.

Explanation:

Let x = 20, y = 10 and z = 5 be the number of dollar bills.

x + y + z = 15 Also

20x + 10y + 5z = 185 Multiply the first equation by 5:

5x + 5y + 5z = 75 Subtract:

15x + 5y = 110 Divide through by 5:

3x + y = 22 There has to be an odd number of $5 bills.

Trial and error:

Let x = 4 then y = 10 then z = 1:

Substitute these into the second equation:

20(4) + 10(10) + 5 = 80 + 100 + 5 = 185.

So the answer is 4 $20 , 10 $10 and 1 $5 bills.