A car travels a certain distance from town A to town B at the speed of 42 km/h and from town B to town A at a speed of 48 km/h. What is the average speed of the car?
Correct Answer:
Explanation:
If two equal distance are covered at different speeds at A km/h and B km/h respectively, then
Average speed during the whole journey = 2AB/(A + B) km/h ∴ Average speed of the car = (2 x 42 x 48) / (42 + 48)
= (2 x 42 x 48)/90
= 44.8 km/h