If you could explain as well how to answer this on a BA2 calculator I would appreciate, thank you!

You are 30 years old today. You want to retire at the age of 55. You expect to live until age 90. You would like to have a monthly income of S12,000 per month in retirement. How much do you have to save per month during your working years in order to achieve your retirement goal? Assume end of period payments. Assume an annual interest rate of 4% in retirement and 6.50 0 during your working life. How much do you have to save per month during your working years in order to achieve your retirement goal? (Round to the nearest cent.)