You are absolutely right.
Daily, there is always something new to be learning in the science world.
D + q = 110......d = 110 - q
0.10d + 0.25q = 20.30
0.10(110 - q) + 0.25q = 20.30
11 - 0.10q + 0.25q = 20.30
-0.10q + 0.25q = 20.30 - 11
0.15q = 9.30
q = 9.30/0.15
q = 62 <==== there are 62 quarters
d = 110 - q
d = 110 - 62
d = 48 <==== there are 48 dimes
Answer:
the left side of the histogram is the mirror image of the right side.
Find how much interest is earned for one year: $3000 x .015 = $45
Use that answer to find how much interest is earned for 15 years: $45 x 15 years = $675
Add original investment to interest for balance: $3000 + $675 = $3675