A thief is spotted by a policeman from a distance of 400 meters. When the policeman started running after the thief, the thief also started running. Assuming the speed of the thief to be 8 km/h and that of the policeman is 10 km/h, how far will the thief have run before he is overtaken by the policeman?
A thief is spotted by a policeman from a distance of 400 meters. When the policeman started running after the thief, the thief also started running. Assuming the speed of the thief to be 8 km/h and that of the policeman is 10 km/h, how far will the thief have run before he is overtaken by the policeman? Correct Answer 1600 meters
Given: Distance between the policeman and thief = 400 meters
Speed of the thief = 8 km/h
Speed of the policeman = 10 km/h
Formula used:
Speed = Distance/Time
Concept used:
Relative speed = Speed of policeman – Speed of thief
Calculation:
Relative speed = 10 – 8
⇒ 2 km/h
Or 2× (5/18)
⇒ 5/9 m/s
Time taken by policeman to overtake the thief = 400/(5/9)
⇒ (400 × 9)/5
⇒ 80 × 9
⇒ 720 seconds
Distance covered by the thief = 720 × 8 × (5/18)
⇒ 40 × 8 × 5
∴ 1600 meters