Ben's new car cost twice as much as his old car. He sold his old car for $1800 and used that to pay off some of the cost of his new car. He still owes another $2000 on his new car. How much did his old car cost, in dollars? Let's answer step by step:
His new car costs 1800 + 2000 = 3800 dollars. His old car cost 3800 / 2 = 1900 dollars. The answer: 1900.