Question

for a train that travels from one station to another at uniform speed 40km/hr and return to final station at speed of 60km/hr.Then its average speed is

Answer 1

average speed = total distance /total time
Let station 1 = s1
station 2=s2

Time=distance /speed

time taken to travel from s1 to s2 =d/40
time taken to travel from s2 to s1=d/60
so total time =d/40+d/60
=d/24

total distance =2d...as distance remains constant


average speed =total distance /total time
= 2d/d/24
=48km /hr