SOLUTION: A coin jar contains nickels, dimes, and quarters. There are 66 coins in all. There are 8 more nickels than quarters. The value of the dimes is $3.20 less than the value of the quar

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Question 1101735: A coin jar contains nickels, dimes, and quarters. There are 66 coins in all. There are 8 more nickels than quarters. The value of the dimes is $3.20 less than the value of the quarters. How many quarters are in the jar?
Found 4 solutions by stanbon, ikleyn, greenestamps, richwmiller:
Answer by stanbon(75887) About Me  (Show Source):
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A coin jar contains nickels, dimes, and quarters. There are 66 coins in all. There are 8 more nickels than quarters. The value of the dimes is $3.20 less than the value of the quarters. How many quarters are in the jar?
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Quantity Eq:: n + d + q = 66 coins
Quantity Eq:: n = q + 8
Value Eq::::: 10d = 25q - 320
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Rearrange::
q+8 + (2.5q-32) + q = 66
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4.5q = 98
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Comment:: Please check your posting. q does not appear to be a whole number.
But, it must be.
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Cheers,
Stan H.
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Answer by ikleyn(52867) About Me  (Show Source):
Answer by greenestamps(13206) About Me  (Show Source):
You can put this solution on YOUR website!


The first tutor had an error in his algebra; the second tutor didn't read the problem correctly. There is a solution to your problem.

Let the number of quarters be q;
then the number of nickels is q+8.
Then, since the total number of coins is 66, the number of dimes is 66-%28q%2B%28q%2B8%29%29+=+58-2q

We are told the value of the dimes is $3.20 less than the value of the quarters. Writing the equation in cents instead of dollars:
10%2858-2q%29+=+25q+-+320
580-20q+=+25q-320
900+=+45q
q+=+20


The number of quarters is 20; so the number of nickels is 28; so the number of dimes is 18.

Answer by richwmiller(17219) About Me  (Show Source):
You can put this solution on YOUR website!
Stan's
q+8 + (2.5q-32) + q = 66
4.5q = 98 should be
4.5q = 90
q=20