A thief seeing a policeman from a distance of 400 m started running at a speed of 16 km/h. The policeman chased him immediately with a speed of 18 km/h and the thief was caught. What is the distance run by the thief before he was caught by the policeman?
Show answer & explanation
Correct answer: A
Explanation
The correct answer is option 1 i.e. 3200 m.
When two persons run in same direction, their relative speed is equal to the difference between their individual speeds.
Relative speed of policeman and thief = 18 - 16 = 2 km/hr
Relative speed in m/sec = 2 × 5/18 = 5/9 m/sec
Now, times taken by policeman to catch the thief = 400/(5/9)
⇒ 720 sec
Now, distance travelled by thief = 720 × 16 × 5/18
⇒ 3200 m