A car covers a certain distance at 54 km/h in 4 hours. How much time will it take to cover the same distance at 72 km/h? MCQ with Answer and Explanation

Explanation:
Downstream speed = 45 / 3 = 15 km/h. Upstream speed = 45 / 9 = 5 km/h. Speed of current = (15 - 5) / 2 = 10 / 2 = 5 km/h.

Explanation:
Perimeter of the track = 4 * 60 = 240 meters. Speed = 12 km/h = 12 * (5/18) = 10/3 m/s. Time required = Distance / Speed = 240 / (10/3) = 240 * 3 / 10 = 72 seconds.

Explanation:
Distance 1 = 50 * 3 = 150 km. Distance 2 = 60 * 2 = 120 km. Total distance = 270 km. Total time = 5 hours. Average speed = 270 / 5 = 54 km/h.