A car travels from a to b at a speed of 20km h and returns at a speed

1.	A car travels from a to b at a speed of 20km h and returns at a speed of 30 km h
Answer» Let us assume the distance between A to B is x km.So , the car travels a total distance of (x+x) = 2x km.Now, the car travels at a speed of 20 km/hr from A to B .So, time taken by the car to reach at the point B from point A is given by,Car travels 20 km in 60 minutes.Car travels x km in (60÷20)×x minutes= 3x minutesNow, in the time of returning the car returns at a speed of 30 km/hr.So, time taken by the car to reach A from B is given by,Car travels 30 km in 60 minutes.Car travels x km in (60÷30)×x minutes= 2x minutes.So , the car takes a total time of ( 3x+2x)=5x minutes.Now , the average speed of the car for the whole journey is given by,In 5x minutes the car covers a distance of 2x km.So, in 60 minutes the car covers a distance of (2x÷5x)×60 km= 24 km.So , the average speed of the car for the whole journey is 24km/hr.

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