In the question, two quantities (I) and (II) are given. You have to solve both quantities to establish the correct relation between Quantity (I) and Quantity (II) and choose the correct option.

Train 'A' of length 360 meters crosses a tree in 12 seconds and the speed of the train is 'y' m/sec. '8y' meter long train 'B' can cross a man in 'x' seconds with speed is 20 m/sec.

Quantity (I): Find the value of (y-x)?

Quantity (II): If train 'A' overtakes train B in 'z' seconds, then find the value of 'z/2'?