Arif starting from X to Y. At the same time Boby starts from Y and goes towards X. Once Arif reaches Y he changes his directions and return to X. Once Boby reaches X, he changes his directions and returns to Y. Though out the journey, Arif travels at 54 kmph and Boby travels at 72kmph. By the time they meet for the second time, Boby covers 36 km more than Arif. Find the distance (in km) between X and Y.