Please help with these two questions!

(4) Assume you pay an annual rent of $36,000 over a period of 44 years paid at the beginning of each year. a) Provided i=0.04, calculate the NPV of this payment stream b) Assume you want to persuade your landlord to pay at the end of each year instead. He would be willing to change the payment scheme -- but only if you pay him an additional $25, 000 in cash premium at the beginning of the rst year. Should you do that? Calculate the resulting difference compared to the beginning-ofthe year scheme under (a)