Answer:
quarters = 10
Step-by-step explanation:
Suppose, number of number of nickels = x
So, number of quarters = x + 7
1 nickel = 5 pennies = 1/20 dollar
1 nickel = $0.05
1 quarter = 25 pennies or 5 nickels = 1/4 dollar
1 quarter = $0.25
Total amount of quarters in the pile of coins = 0.25 * (x+7)
Total amount of nickels in the pile of coins = 0.05 * x
0.25 * (x+7) + 0.05 * x = 2.65
0.25x + 1.75 + 0.05x = 2.65
0.3x + 1.75 = 2.65
0.3x = 0.9
x = 0.9/0.3
x = 3
Number of quarters = x + 7
= 3 + 7
= 10