15. In Section 25-5 we listed four circumstances in which there are potential gains from leasing.

Check them out by conducting a sensitivity analysis on the Greymare Bus Lines lease, assuming that Greymare does not pay tax. Try, in turn,

(a) a lessor tax rate of 50% (rather than 35%), ( b ) immediate 100% depreciation in year 0 (rather than five-year MACRS), ( c ) a three-year lease with four annual rentals (rather than an eight-year lease), and ( d ) an interest rate of 20% (rather than 10%). In each case, find the minimum rental that would satisfy the lessor and calculate the NPV to the lessee.