Question

A car travel from A to B at a speed 20kmh^-1m and returns at a speed of 30kmh^-1.The average speed of the car for the whole journey is​

Answer 1

Answer:

the average speed formula is distance by time taken

Answer 2

Answer:

24 kmph

Explanation:

Average Speed = Total Distance / Total Time

Distance = Speed x Time

Suppose the distance between A and B is y

time taken moving from A to B = y /20 kmph =  y /20 hr  

time taken moving from B to A = y /30 kmph = y /30 hr

Total Time = y / 20 hr  + y / 30 hr

taking L.C.M

              T =30 y+20 y/600

              T= (50/600)x hr

         Total Distance = 2 y

Average Speed = (2y)/[(50/600)(y)] =1200/50 kmph = 24 kmph