How did they get this answer

What is the equal annual amount of money you have to save to guarantee yourself an annual income to perpetuity of $55,000 starting in 42 years from now? You make the first payment in two years from now and the last payment in 42 years (i.e., you make payments at t 2, 3,4,.42; and you will receive the first payment of the perpetuity at t 42). Assume an interest rate of 7% (EAR). The present value of the perpetuity: $55,000 1 !(14 4T]- 1.0741 = $49,037.66 0.07 The present value of the perpetuity must be equal to the present value of your contributions to your bank account. You make 41 payments starting in year 2. $49,037.66 0.07 11- C = $3,917.41 (1 + 0.07)41-107