Question

You have 59 total coins for a total of $12.05. You only have quarters and dimes. How many of each coin do you have?

Answer 1

let x = # of quarters let y = # of dimes
0.25x+0.1y=12.05 x+y=59
0.25(59-y)+0.1y=12.05 x=59-y
14.75-0.25y+0.1y=12.05 x=59-18
-0.15y=12.05-14.75 x=41
-0.15y=-2.7
y=18

therefore, you have 18 dimes and 41 quarters