Question

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

Answer 1

hello ji.

Distance travelled by the train = 480 km

Let the speed of the train be x kmph

Time taken for the journey = 480/x

Given speed is decreased by 8 kmph

Hence the new speed of train = (x – 8) kmph

Time taken for the journey = 480/(x – 8)

480/x-8 - 480/x = 3

480(x-x+8)/ x(x-8) = 3

480/3 ×8 = x² - 8x

1280 = x²– 8x

x2– 8x – 1280 = 0

On solving we get x = 40

Thus the speed of train is 40 kmph