Answers: 17 quarters and 51 dimes
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Work Shown:
x = number of quarters
3x = number of dimes
0.25x = value of just the quarters, in dollars
0.10(3x) = 0.30x = value of just the dimes, in dollars
0.25x+0.30x = 0.55x = total value in dollars
0.55x = 9.35
x = (9.35)/(0.55)
x = 17
Alison has 17 quarters and 3x = 3*17 = 51 dimes
17 quarters = 17*0.25 = $4.25
51 dimes = 51*0.10 = $5.10
17 quarters + 51 dimes = $4.25 + $5.10 = $9.35
The answers are confirmed.