A series of four annual constant-dollar payments beginning with $10,000 at the end of the first year

Question:

A series of four annual constant-dollar payments beginning with $10,000 at the end of the first year is growing at the rate of 8% per year. Assume that the base year is the current year (n = 0).
If the market interest rate is 15% per year and the general inflation rate () is 7% per year, find the present worth of this series of payments, based on
(a) Constant-dollar analysis
(b) Actual-dollar analysis