A merchant van covers 120 km at 40 km/h, 180 km at 60 km/h and 100 km at 50 km/h. Find the net average speed. MCQ with Answer and Explanation

Explanation:
Total distance = 60 + 40 = 100 km. Time 1 = 60 / 15 = 4 hours. Time 2 = 40 / 20 = 2 hours. Total time = 6 hours. Average speed = 100 / 6 = 16.66 km/h.

Explanation:
Speed = 54 * (5/18) = 15 m/s. Distance in 20 seconds = Speed * Time = 15 * 20 = 300 meters.

Explanation:
Total distance to be covered = 140 + 160 = 300 meters. Relative speed = 60 + 40 = 100 km/h = 100 * (5/18) = 250/9 m/s. Time = Distance / Speed = 300 / (250/9) = 300 * 9 / 250 = 10.8 seconds.