Question

A train covers a distance of 480km at a uniform speed. If the speed had been 8km/h less, then it would have taken 3 hours more to cover the same distance. Find the usual speed of the train. This question is from Quadratic equation. Plzz solve it i will mark brainlist

Answer 1

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)

1280 = x2– 8x
x2– 8x – 1280 = 0
On solving we get x = 40
Thus the speed of train is 40 kmph

Answer 2

hey friend!!?

your answer is "40"

Explaination ☞
______-

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

=>1280 = x²– 8x

=> x²– 8x – 1280 = 0

On solving we get

=> x = 40

Thus the speed of train is 40 kmph

hope it will help you