A train travels a distance of 480 km at a uniform speed.

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)�

1280 = x2�– 8x

�x2�– 8x – 1280 = 0

On solving we get x = 40

Thus the speed of train is 40 kmph