Robin has a debt of RM15,000 that is due at the end of 10 years. In order to liquidate her debt, she is advised to make payment of RM X now, RM 2X in 5 years' time and another payment of RM 3X in 12 years' time. Calculate the value of X if the annual effective interest rate is 8% for the first 6 years and 10% for the subsequent years