can you please show me your work (calculations)

You plan to retire at age 60 years, you expect that the last 3 years of service the annual pay will average at $50,000. If your pension plan agreement allows 3% factor payment, and that upon retirement you will have 21 years of service. Calculate the annual retirement payment to be received from pension $31,500 $20,000 $30,000 $23,600