Please help me to solve this question. I'm condused.

Example: An investor plans to retire 35 years from today and have sufcient savings to guarantee $48,000 each year for 20 years. Assume retirement withdrawals will be made a_t the beginning of each of the 20 years. The investor estimates that at the time of retirement, he can sell his business for $200,000. The expectation is that interest rates will be relatively stable at 8% per year for the next 35 years. Thereafter, the interest rate is expected to decline to 6% per year forever. The investor wants to make equal annual deposits at the m of each of the next 35 years. How much should be deposited each year in order to meet the stated objective