Problema Solution

A student makes a $10.50 purchase at the bookstore with $20 bill. The store has no bills and gives the change in quarters and fifty-cent pieces. There are 30 coins in all. How many of each kind are there?

Answer provided by our tutors

the change made:

20.00 - 10.50 = 9.50


let 'x' represent the number of quarters in change, then '30-x' represents the number of 50-cent pieces


9.50 = 0.25x + (30-x)0.50

solving for 'x' we have x=22


30-22 = 8


the change consisted of 22 quarters and 8 50-cent pieces