Question

A train travels a distance of 480 km at a uniform speed if the speed had been 8 kilometre per hour less than it would have taken 3 hours more to cover the same distance we need to find the speed of a train

Answer 1

ANSWER
..............

 ***********Suppose the speed of the train is Y km/h.

It takes 480Y hours to travel

                          , but if the speed were

8 km/h slower, it would take 480Y−8 hours.

 we've got the equation:
480Y−8 = 480Y +3

Multiple both sides of the equation by Y(Y−8). 


480Y=480(Y−8)+3Y(Y−8)


Y2−8Y−1280=0
(−40)(Y+32)=0
Y=40,−32

, so the speed
is Y=40 km/h.

so the difference  is three hours