Question

A cash register contains only five dollar and ten dollar bills. It contains twice as many five's as ten's and the total amount of money in the cash register is 640 dollars. How many ten's are in the cash register?

Answer 1

Answer:

Let the number of five's = 2x = 2x × 5 = 10x

Then the number of ten's = x = x × 10 = 10x

10x + 10x = 640

20x = 640

x = 32

There are 32 ten dollar bills.