Satish, Bhavya and Abhishek entered into a partnership with Rs 15000, Rs 18000 and Rs. 24000 respectively. Abhishek joined them after ‘x’ months and Bhavya left ‘x’ month before the end of year. If they share profit at the end of the year. If they share profit in the ratio 10: 9: 12. Find the value of ‘x’.