Question

A motorcyclist drives from A to B with a uniform speed of 20 kmh and returns back with speed of
30 km/h Find his average speed?
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Answer 1

Answer:

Let distance between A and B is D

Then, time taken by motorcyclist with uniform speed 30 km/h ,T₁ = distance/speed = D/30 hrs

Again, they return with uniform speed 20 km , so time taken by motorcyclist , T₂ = D/20 hrs

Now, average speed of motorcyclist = total distance/total time taken

= (D + D )/(D/30 + D/20) km/h

= 2 × 30 × 20/(30 + 20) km/h

= 24 km/h

Answer 2

Answer:24 kmph

Explanation:

Let the distance between A and B be x time to go from A to B is x/20 time taken to go from B to A is x/30 total diatance is x+x=2x total time is x/12 so,avg speed =2x/(x/12) =24 kmph