Question 381914: solve the following using a system of equations;
Rod has 40 coins, all dimes and quarters, worth $7.60. How many dimes and how many quarters does he have?
Answer by stanbon(75887)   (Show Source):
You can put this solution on YOUR website! Rod has 40 coins, all dimes and quarters, worth $7.60. How many dimes and how many quarters does he have?
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Equations:
Quantity Eq. d + q = 40
Value Eq:: 10d+25q = 760
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Multiply thru the Quantity equation by 10 to get:
10d + 10q = 10*40
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Subtract that from the Value Eq and solve for "q":
15q = 360
q = 24 (# of quarters)
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Substitute into d+q = 40 and solve for "d":
d + 24 = 40
d = 16 (# of dimes)
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Cheers,
Stan H.
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