SOLUTION: Joe has a collection of nickels and dimes that is worth $6.05. If the number of dimes was doubled and the number of nickels was decreased by 10, the value of the coins would be $9.
Question 179554: Joe has a collection of nickels and dimes that is worth $6.05. If the number of dimes was doubled and the number of nickels was decreased by 10, the value of the coins would be $9.85. How many dimes does he have? Answer by nerdybill(7384) (Show Source):
You can put this solution on YOUR website! Joe has a collection of nickels and dimes that is worth $6.05. If the number of dimes was doubled and the number of nickels was decreased by 10, the value of the coins would be $9.85. How many dimes does he have?
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Let d = number of dimes
and n = number of nickels
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From:"Joe has a collection of nickels and dimes that is worth $6.05."
.10d + .05n = 6.05 (equation 1)
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From:"If the number of dimes was doubled and the number of nickels was decreased by 10, the value of the coins would be $9.85"
.10(2d) + .05(n-10) = 9.85
.20d + .05n-.5 = 9.85
.20d + .05n = 10.35 (equation 2)
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Solve equation 1 for n:
.10d + .05n = 6.05
.05n = 6.05 - .10d
n = 121 - 2d
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Plug the above into equation 2 and solve for d:
.20d + .05n = 10.35
.20d + .05(121 - 2d) = 10.35
.20d + 6.05 - .1d = 10.35
.10d + 6.05 = 10.35
.10d = 4.3
d = 43 dimes
