Can you help me to fill this Excel document, and please provide Excel formulas?

6. Perpetuities are often used to value merger and acquisition targets. a) What is the present value of a stable perpetuity of $100,000 per year that starts at the end of year one and continues to infinity? The appropriate discount rate is 10%. b) What is the present value of a stable perpetuity of $100,000 per year that starts at the end of year five and continues to infinity? The appropriate discount rate is 10%. c) What is the present value of a growing perpetuity that starts at $50,000 at the end of year one and grows at a 4% annual rate? The appropriate discount rate is 10%. d) What is the present value of a growing perpetuity that starts at $50,000 at the end of year five and grows at a 4% annual rate? The appropriate discount rate is 10%