Answer: He owes $17,000 on his new car.
Explanation: Because Tyler traded his car which was worth $5,000 on a $15,000 car this would decrease the cost by $5,000 due to the car he traded in, but since he still owed $7,000 on the car that he traded in he will still have to pay that off, which was grouped into the bill of the new car that he bought.