Please help figure out how to do these problems

(19) Marcel Thiessen purchased a home for 203,800 and obtained a 15 - year, fixed rate mortgage at 10 after paying a down payment of 10% Of the first month's mortgage payment, how much interest and how much is applied to the principal . (20 ) you purchase a collage for 180,000. you Obtain a 20 year fixed rate mortgage loan at 119% after paying a down payment of 3090, of the second month's mortgage payment, how much is interest and how much is applied to the principle