A policeman follows a thief, who is 840 metres ahead of him. The thief and the policeman run at a speed of 7.5 km/h and 9 km/h, respectively. What distance (in km) is run by the thief before he is nabbed by the policeman?
Show answer & explanation
Correct answer: D
Explanation
The correct answer is option 4 i.e. 4.2.
Relative speed of policeman and thief = 9 - 7.5 = 1.5 km/h
Time taken by the policeman to nab the thief = Distance(in km)/Relative speed
⇒ 0.84/1.5 = 0.56 hours
Distance covered by thief before the policeman nabbed him = Speed of thief × Time
⇒ 7.5 × 0.56 = 4.2 km