Question

Jennifer has 25 coins with a total value of $4.25. The coins are quarters and nickels. How many of each does she have?

Answer 1

15 quarters, 10 nickels

Explanation:

`q+n=25`

`0.25q+0.05n=4.25`

multiply the first equation by -0.25 and add the second equation to it

`-0.25q-0.25n=-6.25\\0.25q+0.05n=4.25`
________________

`-0.2n=-2`

`n=(-2)/(-0.2) =10` has 10 nickels

`q=25-n=25-10=15` has 15 quarters

10(.05) +15(0.25) = 0.5 + 3.75 = 4.25

Hope this helps