Question 177878This question is from textbook
: A collection of 70 coins consisting of dimes, quarters, and half-dollars has a value of $17.75. There are three times as many quarters as dimes. Find the number of each kind of coin.
This question is from textbook
Answer by MathTherapy(10551)   (Show Source):
You can put this solution on YOUR website! Let the amount of dimes be d, then the amount of quarters are 3d
Let the amount of half-dollars be h
Then d + 3d + h = 70, or 4d + h = 70
Then d(.10) + 3d(.25) + h(.5) = 17.75, or .1d + .75d + .5h = 17.75, or .85d + .5h = 17.75
4d + h = 70 -----------(i)
.85d + .5h = 17.75 -------(ii)
Multiply eq. (i) by - .5 -2.00d - .5h = - 35 -------(iii)
Add eq (ii) & (iii) -1.15d = - 17.25
d = 15
4(15) + h = 70
60 + h = 70
h = 10
Therefore, there are 15 dimes - $1.50
there are 45 quarters - $11.25
there are 10 half-dollars - $5.00
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