Answer:
63 dimes
Explanation:
Set up a system of equations where d is the number of dimes and q is the number of quarters:
d + q = 106
0.1d + 0.25q = 17.05
Solve by elimination by multiplying the top equation by -0.25 to eliminate q:
-0.25d - 0.25q = -26.5
0.1d + 0.25q = 17.05
Add together and solve for d:
-0.15d = -9.45
d = 63
So, there were 63 dimes in the piggy bank