Laura and Martin obtain a 25-year, $180,000 conventional mortgage at 10.0% on a house selling for $200,000. Their monthly mortg payment, including principal and interest, is $1636.20. a) Determine the total amount they will pay for their house. b) How much of the cost will be interest? c) How much of the first payment on the mortgage is applied to the principal? a) The total amount that Laura and Martin will pay for their house is $ (Round to the nearest dollar as needed.) b) They will pay a total of $ in interest. (Round to the nearest dollar as needed.) c) Of the first mortgage payment, $ is applied to the principal. (Round to the nearest cent as needed.)