Answer: There are 57 quarters and 33 dimes.
Step-by-step explanation:
let x = Number of quarters
y= Number of dimes
As per given , we have
x+y = 90 (i)
0.25x+0.10y= 17.55 (ii)
Multiply 10 on both sides of (ii)
2.5x+y= 175.5 (iii)
Eliminate (i) from (iii) , we get
1.5x = 85.5
⇒ x= 57
Put value of x in (i) , we get
57+y=90
⇒ y= 90-57
⇒ y= 33
Hence, there are 57 quarters and 33 dimes.