A quarter is equivalent to 25 cents or $0.25 and a nickel is equal to 5 cents or $0.05. In the given in this item, if there are x nickels then, there are x + 7 quarters. With these and the total amount known, we can now compute for the value of x.
(x)(0.05) + (x + 7)(0.25) = 2.65
Simplifying,
0.05x + 0.25x + 1.75 = 2.65
Simplifying further,
0.3x = 0.9
The value of x from the equation is 3. Hence, there are 10 quarters.