1. An automatic process controller will eliminate the current manual control operation. Annual cost of the current method is $7,000. If the controller has a service life of 15 year and an expected market value of 8% of the first cost, what is the maximum economical price (in dollar) for the controller? Ignore interest.
2. Your monthly mortgage payment (principal plus interest) is $1, 100. If you have a 12-year loan with a fixed interest rate of 0.75% per month, how much did you borrow from the bank to purchase your house (rounded to the nearest whole dollar)?
3. What is the principal (to the nearest whole dollar) remaining after 24 monthly payments made on a $55,000 five-year loan? The annual interest rate is 3% nominal compounded monthly.