Question

the average speed of the express train is 20 km/hr more than the average speed of a passenger train to cover a distance of 360 kilometres .Express train takes 3 hours less than that of the passenger train find the average speed of passenger train and Express train.

Answer 1

hope the answer may help u

Answer 2

let average speed of passenger train =x km/h
and average speed of express train = x +20 km/h

we know,
time = distance/speed

according to question ,
time taken by passenger train =time taken by express train + 3

so, 360/x -360/(x +20) = 3
120{ 1/x -1/( x +20) } = 1
120×20 = x² +20x
x² +20x -2400 =0
x ={ -20±√(400+9600)}/2
=(-20±100)/2
=40 , -60
so,
speed of passenger train =40 km/h
speed of express train =40+20 =60km/h