I need help with these simple interest questions.

On July 14, Fat Tires Lid. borrowed $10,000.00 with an interest rate of 8.1%. The loan was repaid in full on December 20, with payments of $2900.00 on September 19 and $3000.00 on November 1. What was the final payment? The final payment was $. (Round the final answer to the nearest cent as needed. Round all intermediate values to six decimal places as needed.)An investor purchased a 182-day, $25,000.00 T-bill on its issue date for $24,584.44. After holding it for 11 days, she sold the T-bill for a yield of 1.86%. (a) What was the original yield of the T-bill? (b) For what price was the T-bill sold? (c) What rate of return (per annum) did the investor realize while holding this T-bill? (a) The original yield of the T-bill was %. (Round the final answer to two decimal places as needed. Round all intermediate values to six decimal places as needed.) (b) The T-bill sold for $]. (Round the final answer to the nearest cent as needed. Round all intermediate values to six decimal places as needed.) (c) The investor realized a rate of return of%. (Round the final answer to two decimal places as needed. Round all intermediate values to six decimal places as needed.)