A policeman spotted a thief 40 metres ahead of him. The moment they both saw each other they started running in the same direction on the same track. The thief was running at 10 m/sec and the policeman was chasing him at the speed of 12 m/sec. How much distance (in metres) the policeman needed to cover to catch the thief?

240

Relative speed = ( 12 - 10 ) = 2 m/sec

Time = \(\frac{40}{2}\) = 20 sec

Distance run by Policeman is = 20 × 12 = 240 m

So ,  The distance thief run by policeman is 240 m