21. In order to purchase his home, Oscar Summers borrowed $32,000 from the bank at a rate of 10% and must repay it in 3 equal installments at the end of each of the next 3 years. What percentage of the payment in the third year represents interest? a) 8.53% b) 11.64% c) 10.53% d) 9.09% e) 12.32%