A policeman noticed a thief at a distance of 500 metres. The policeman started running and the thief also started running at the same time. The thief is running at a speed of 15 km/h. It took 15 minutes for the policeman to catch the thief. Find the speed of the policeman (in km/h).
Show answer & explanation
Correct answer: B
Explanation
The correct answer is Option 2 i.e. 17.
Let the speed of the policeman be x km/h
The thief is running at a speed of 15 km/h, and the initial distance between them is 500 meters or 0.5 km.
The policeman catches the thief in 15 minutes, which is 15/60 = 1/4 hrs
Distance covered by the thief in 15 minutes = 15 × 1/4 = 3.75 km
Since the policeman covers the same distance as the thief plus the initial 0.5 km gap in the same 15 minutes,
The total distance covered by the policeman = 3.75 + 0.5 = 4.25 km
Now, using the time of 1/4 hour, the speed of the policeman
⇒ x = 4.25/(1/4)
⇒ x = 4.25 × 4 = 17 km/hr
The speed of the policeman is 17 km/hr