Question

If an object cover three equal distance with speed v1 v2 v3 then what is the average speed of body

Answer 1

Heya!!

As the question is abt average speed, don't take average by adding the the 2 speeds and dividing them by 3. That is absolutely wrong.
The total average speed is the total distance divided by the total time.

d1 with a speed of v1  = d1=d
d2 with a speed of v2  =d2=d
d3 with a speed of v2  =d3=d

total distance(td)= d1+d2+d3=d+d+d =3d

time:
t1 = d/v1
t2=d/v2
t3=d/v3

total time= d(v1+v2+v3)/v1v2v3

average speed = total distance / total time
                         =  3d*v1*v2*v3             3 *v1*v2*v3
                             -----------------    =    -------------------
                             d(v1+v2+v3)             (v1+v2+v3)

Hope this helps u:)))))