A thief saw a policeman, and he started running at a speed of 18 m/s. After 12 seconds, the policeman starts running behind the thief at a certain speed. If the policeman covered 864 meters distance to reach the thief, then the speed (in m/s) of the policeman is:
24
Relative speed = Distance / Time = 864 / 12 = 72 m/s. Since the thief was running at 18 m/s, the speed of the policeman is 72 + 18 = 90 m/s. So, the answer is D) 24 m/s.
Rishi travels 198 km at 66 km/hr, the next 584 km at 73 km/hr and the next 656 km at 82 km/hr. What is his average speed (in km/hr) for the whole journey? (Round off your answer to two decimal places)