Question of The Day25-04-2022

A car travels from A to B at a speed of 40 km/hr, travels back from B to A at a speed of 30 km/hr and again goes from A to B at a speed of 60 km/hr. What is the average speed of the car?

Correct Answer : c ) 40 km/hr

Explanation :

Let us assume that the distance between A and B is X km.

Trip 1: The car goes for a distance X at 40 km/hr,

Trip 2: The car goes for a distance X at 30 km/hr,

Trip 3: The car goes for a distance X at 60 km/hr,

Total distance covered by the car = 3X.

Time taken by the car in Trip 1 = X/40 hr.

Time taken by the car in Trip 2 = X/30 hr.

Time taken by the car in Trip 3 = X/60 hr.

Total time taken by the car = X/40 + X/30 + X/60

Total time taken by the car = (3X + 4X + 2X)/ 120

Total time taken by the car = 9X/ 120

Average speed of the car = Total Distance travelled/ Total time taken

Average speed of the car = 3X/ (9X/120)

Average speed of the car = 40 km/hr

Hence, (c) is the correct answer.

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