A thief is stopped by a policeman from a distance of 150 metres. When the policeman starts the chase, the thief also starts running. Assuming the speed of the thief as 7 km/hr and that of policeman as 9 km/hr, how far the thief would have run, before he is over- taken by the policeman?

• 420 metres
• 630 metres
• 315 metres
• 525 metres