A policeman is chasing a thief at a speed of 12 km/h, and the thief is running at a speed of 8 km/h. If the policeman started 30 minutes late, find the time taken by the policeman to catch the thief.
Show answer & explanation
Correct answer: B
Explanation
The correct answer is option 2 i.e. 60 minutes.
The speed of the policeman = 12 km/h
The speed of the thief = 8 km/h
Relative speed = 12 - 8 = 4 km/h
30 minutes = 1/2 hours = 0.5 hour
The thief covers = 8 × 0.5 = 4 km
Time required for the policeman to cover 4 km at a relative speed = 4/4 = 1 hour = 60 minutes
Therefore, the policeman will take 60 minutes to catch the thief.