In order to pay for school, you borrow $22,000 at 12 percent/year compounded monthly. You do not pay back any of it until the end of the first month following year 4, and you intend to have it paid off by the end of year 7. 

a. What are your monthly payments during years 5, 6, and 7? 

b. How much interest is in the sixtieth month's payment? How much principal? 

c. How much interest is in the sixty-fourth month's payment? How much principal? 

d. How much interest is in the sixty-eighth month's payment