Please show formula

Your friend promises you a perpetuity of $1.5 every year. The first payment occurs in year 1, the interest rate is 10% every year, years 9 and 11 have no payment, and year 10 has a payment of $6 because of the mistake made by your friend. Except for these three years, the payment is always $1.5 in other year. Which of the following is right about its present value at time zero? a. $14.99 b. $15.99 c. $15.57 d. $16.57 e. None of the above Clear my choice