A family made a down payment of $300
and borrowed the balance on a set of
encyclopedias that cost $750. The
balance with interest was paid in 9
monthly payments of $57 each and a
final payment of $21. The amount of
interest paid was what percent of the
amount borrowed? Choose the correct choice:
A) 6%  B) 12%  C) 14%  D) 18.66%  E) 20%
interest paid = 57*9+21 - 450= 
<gadget id="calculator">57*9+21 - 450</gadget>
<output>84</output>
84   % off the balance= (84/450) * 100 = 18.66%   Answer is 18.66%.
<result>D</result>
A family made a down payment of $300
and borrowed the balance on a set of
encyclopedias that cost $750. The
balance with interest was paid in 9
monthly payments of $57 each and a
final payment of $21. The amount of
interest paid was what percent of the
amount borrowed?