Question 143545
90.15

Let n be the number of nickels
Dimes = 2n - 6 --> d = 2n - 6 
Quarters = 4n + 3  --> q = 4n +3 


9015 = 5n + 10d + 25q = n + 10*(2n - 6) + 25*(4n +3)
9015 = 5n + 20n - 60 + 100n + 75
9015 = 125n - 15
9000 = 125n
72 = n

d = 144 -6 = 138
q = 291

Does that check?
0.25*291 + 0.1*138 + 0.05* 72 = 90.15