Question 1136814
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Let N = # of nickels.


Then the number of dimes = (N-12),
and the number of quarters = 6*(N + (N-12)) = 6*(2N-12) = 12N - 72.


The the total of money equation is


5N + 10*(N-12) + 25*(12N-72) = 4380  cents.


Simplify and solve for N.


Then evaluate the number of dimes and the number of quarters.
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This problem is to be solved using one single equation for one unknown.