A person covers a distance of 120 km at 30 km/h and another 180 km at 45 km/h. Find his average speed for the whole journey. MCQ with Answer and Explanation

Explanation:
Total distance = 110 + 190 = 300 meters. Speed = 300 / 20 = 15 m/s. In km/h = 15 * (18/5) = 54 km/h.

Explanation:
Upstream speed = 16 / 4 = 4 km/h. Upstream Speed = Speed in still water - Current speed => 4 = Speed in still water - 1 => Speed in still water = 5 km/h.

Explanation:
Speed of train = 140 / 7 = 20 m/s. In km/h = 20 * (18/5) = 72 km/h.