George buys a car every 6 years for $18,000. He trades in his current car to count as the 20% down payment. The rest is financed at a nominal 12% interest with monthly payments over 6 years. When the loan is paid off, he trades in the car as the "20%" down payment on the next car, which he finances the same way

Jeanette has similar tastes in cars, and the dealer will count her trade-in vehicle as worth 20%. She has paid cash for old cars in the past, so she now has $14,400 in cash for the other 80% cost of a new car. In 6 years, her vehicle will be worth the "20%" down payment. She wants to make a monthly deposit so that she has the other 80% of the vehicle's cost in 6 years. Her savings account has a nominal annual interest rate of 6% with monthly compounding.

What is George's payment? What is Jeanette's deposit? If Jeanette also deposits the difference in a retirement account that pays 9% nominal interest with monthly compounding, what does she have for retirement after 40 years?