Answer:
16 quarters and 12 dimes
Explanation:
Let 'q' be the number of quarter and 'd' be the number of dimes.
So he has,
......................... (i)
It is given that John has 4 more quarters than dimes, so we have,
............................. (ii)
Putting the value of 'q' in equatioi (i), we get,





Putting d = 12 in the equation (ii), we get,

Therefore, John has 16 quarters and 12 dimes.
You can also verify the sum by multiplying 16 quarters with its value and adding the value of 12 dimes, you will get $5.20.