A 200 m long train crosses a man standing on a 300 m long running train. If the speeds of the trains are 30 km/h and 40 km/h, find the time taken for the first train to cross the man.

The time depends on whether the trains are moving in the same or opposite directions, which isn't specified. If same direction: relative speed = 10 km/h, time = 200/(10*5/18) = 72 sec. If opposite: relative speed = 70 km/h, time = 200/(70*5/18) = 10.3 sec. Since both scenarios are possible and neither matches options A-C, 'Can't be determined' is correct.