Today, you and your best friend decided to buy a perpetuity together. The perpetuity promises to pay $10 each year forever. You will need the payments from the perpetuity for years 1,2,.20, and then your best friend would become the beneficiary of yearly payment 21 and onwards, forever. If the relevant discount rate is 10%, what will be your share in purchasing this perpetuity today?

a. $10.00

b. $14.86

c. $85.14

d. $100.00

please show excel formulas to explain answer