X and Y entered into a partnership investing Rs. 16,000 and Rs. 12,000, respectively. After 3 months, X withdrew Rs. 5000 while Y invested Rs. 5,000 more. After next 3 more months Z joins the business with a capital of Rs. 21,000. The share of Y exceeds that of Z, out of a total profit of Rs. 26,400 after one year, by