It's not compounded interest, you just get $3.20 every year.
$100 * 0.032 = $3.20
$3.20 * 3 years = $9.60
The value for the missing term is -175.
It will cost $33.
Since wood cost $ .60 sq ft, you can assume she needs to buy 55 sq ft because she will need to buy enough to have 54.3 square ft.
55 x $ .60 = $33
$32.58 would be he total for the 54.3 sq ft and .42 cents would be for the left over .7 sq ft that she didn’t use
