Answer
(a) $107,787$
(b) $17,287$
Work Step by Step
(a) We first find the total amount that will be paid at the end of three years:
$$ 90,500\times (1.06^3) \\ = 107,787$$
(b) Subtracting the original amount, the amount paid in interest is:
$$ =107,787-90,500 \\ = 17,287$$
