please help with thos sum 18

Charmaine obtains a loan for home renovations from a bank that charges simple interest at an annual rate of 15%. Her loan is for - $13,800 for 84 days. Assume each day is 365 of a year. Answer each part below. Do not round any intermediate computations, and round your final answers to the nearest cent. If necessary, refer to the list of financial formulas. (a) Find the interest that will be owed after 84 days. X (b) Assuming Charmaine doesn't make any payments, find the amount owed after 84 days