A courier driver logs 3 hours at 50 km/h and the next 2 hours at 60 km/h. Find the combined average speed. MCQ with Answer and Explanation

Explanation:
Let distance be d. d/16 + d/12 = 7 => (3d + 4d) / 48 = 7 => 7d / 48 = 7 => d = 48 km.

Explanation:
When X covers 200m, Y covers 180m. When Y covers 200m, Z covers 190m. Thus, when Y covers 180m, Z covers 190 * (180 / 200) = 171m. Therefore, when X covers 200m, Z covers 171m. X beats Z by 200 - 171 = 29 meters.

Explanation:
Let the half distance be d. d / 40 + d / 20 = 6 => 3d / 40 = 6 => 3d = 240 => d = 80 km. Total distance = 2d = 160 km.