Using a financial calculator, provide a solution to each of the following situations. 

a. Lisa Okoye owes a debt of $42,000 from the purchase of her new sport utility vehicle. The debt bears annual interest of 7.8% compounded monthly. Lisa wishes to pay the debt and interest in equal monthly payments over eight years, beginning one month from now. What equal monthly payments will pay off the debt and interest? 

b. On January 1, 2024, Celmira Jalloh offers to buy Dave Contee’s used snowmobile for $8,000, payable in five equal annual instalments, which are to include 7.25% interest on the unpaid balance and a portion of the principal. If the first payment is to be made on December 31, 2024, how much will each payment be?