SOLUTION: A student makes a $10.50 purchase at the bookstore with a $20 bill. The store has no bills and gives the change in quarters and fifty-cent pieces. There are 30 coins in all. How ma

Algebra ->  Functions -> SOLUTION: A student makes a $10.50 purchase at the bookstore with a $20 bill. The store has no bills and gives the change in quarters and fifty-cent pieces. There are 30 coins in all. How ma      Log On


   

Question 614522: A student makes a $10.50 purchase at the bookstore with a $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?
How many quartes are there in the change?
How many fifty-cent piece are there?
Answer by asuar010(338) About Me  (Show Source):
You can put this solution on YOUR website!
let x be the number of quarters and y be the number of 50-cents pieces... then the change was 9.5 and the equations become x%2By=30+and+0.25x%2B0.5y=9.5 then 0.25%2830-y%29%2B0.5y=9.5 then 7.5-0.25y%2B0.5y=9.5 then 0.25y=2.5 so y=8 and x=22