i have the answer to this question but i need it explained so i can understand where the numbers come from!

help with calculating dates, explained

Appendix AA-45 Time (days) 3. Find the effective rate of interest for each of the loans in Problem 2. Use the answers you calculated in Problem 2 to solve these problems; round to the nearest tenth percent. Maturity value Discount rate Effective rate a. $7,000 2% 90 b. $4,550 8.1% 110 c. $19,350 12.79 55 d. $63,400 10% 90 e. $13.490 7.9% 200 1 f. $780 12 65 Appendix AA-45 Effecthe male and 30 8.33 turity value The days 90 110 55 90 200 10.30 835 57.000 54.550 $19.350 & $63.400