A thief running at 11km/h is chased by a policeman at a speed of 13 km/h . If the thief is ahead by 900 m , how much time will the policeman take to catch the thief after starting the chase ?
Show answer & explanation
Correct answer: D
Explanation
The correct answer is option 4 i.e. 27 min.
Thief’s speed = 11½ = 23/2 km/h
Policeman’s speed = 13½ = 27/2 km/h
Relative speed = (27/2 - 23/2) = 4/2 = 2 km/h
Distance gap = 900 m = 0.9 km
Time = Distance / Relative speed = 0.9 / 2 = 0.45 hours
Convert to minutes:
0.45 × 60 = 27 minutes