SOLUTION: A child’s piggy bank contains 35 coins and a total of $6.25. The bank contains quarters, dimes and nickels. There are twice as many dimes as there are nickles. How many of

Let N be the number of nickels.

Then the number of dimes is 2N, according to the condition.

Hence, the number of quarters is (35-N-2N) = (35-3N).


The nickels contribute  5N             cents towards the total.

The dimes contribute    10*(2N) = 20N  cents towards the total.

The quarters contribute 25*(35-3N)     cents towards the total.


So, your balance equation is

5N + 20N + 25*(35-3N) = 625  cents.    (<<<---===  you counted all the cents)


Simplify and solve for N step by step.

25N + 875 - 75N = 625  ====>  -50N = 625 - 875 = -250  ====>  N =  = 5.


Answer. 5 nickels,  10 dimes and 35-5-10 = 20 quarters.


Check.  Can you check it on your own ??

    This problem is FOR ONE UNKNOWN.

    Therefore, I made all efforts from my side to solve it as the problem in ONE UNKNOWN.