Question

If a car covers 2\5 of the total distance with v1 speed and 3/5 ditance with v2 then average speed is

Answer 1

avg speed =2v1 v2/v1+v2

Answer 2

speed=distance/time
t1=(2/5x)/V1
t2=(3/5x)/v2

avg speed=d1+d2/t1+t2
=x/[(2/5xv1)+3/5xv2)]
x/[(2xv1+3xv2)/5]
=5/(2v1+3v2)