Question

on a 120 km track A train travels the first 30 kilometre at uniform speed of 30 km per hour calculate the speed with which the train should move the rest of the track so as to get the average speed of 60 km per hour for the entire trip​

Answer 1

train travel 30 km at speed of 30km/h

as speed is 30km per hour So time taken is 1 hour

For entire trip average speed = 60 km/h

time taken = 120/60 = 2 h

First 30 km it travels in 1 hr

so rest 90 km it travels in 1 hr as total time taken 2 hr

So speed = 90km/h