Question

A motorcyclist drives from a to b with a uniform speed of 30 km/hr and returns back with a speed of 20 km/he find its average speed

Answer 1

let the distance be x
while going........
d=xkm
speed=30km/hr
time=d/s=x/30

while coming........
d=x
speed=20km/hr
time=x/20

now,avg speed=total distance /total time 
                         =x+x/x/20+x/30
                         =2x/5x/60
                         =2*12
                         =24km/hr

Answer 2

Answer:

Explanation:

(A)●------------------------------------●(B)

Suppose that the body covered the distance from A to B

Let the distance between those two points be d

Speed1 = 30km/h

Time 1 = distance / speed

= d/30 h

Speed while returning = 20km

Time 2 = d/20 h

Average speed = total distance covered / total time taken

=( d+d) ÷ (d/20) +(d/30)

= 2d ÷ (3d+2d) / 60

= (12)(2)

= 24

So, the average speed was 24 km/h.

Hope it helped you

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