A customer approaches you to advise him on his investment for retirement. He plans to open a unit trust account with RM1,000 with an auto-debit of RM100 per month. The unit trust account is expected to earn a dividend of 4% annually. In this case, a. How much money he could accumulate if he starts his investment at 25-year-old and plans to retire at 55-year-old? (6 marks) b. How long he could use his money after retirement if he withdraw RM500 as a monthly allowance after retires