A seller wants $120,000 for his home and still owes $20,000 of his original loan at 7%. The current interest rate is 12%. A buyer can pay $60,000 down and wants to carry a mortgage that includes the seller's $20,000 existing mortgage and the remaining $40,000 for a total of $60,000 at an interest rate of 10%. What kind of mortgage loan is this? Explain.