A train travels a distance of 480 km at a uniform speed. If the speed had been 8 km/h less, then it would have taken 3 hours more to cover the same distance. Find the speed of the train.
40 kmph
Distance travelled by the train = 480 km
Let the speed of the train be x kmph
Time taken for the journey = 480x
Given speed is decreased by 8 kmph
Hence the new speed of train = (x–8) kmph
Time taken for the journey = 480x−8
⇒ 480x−8−480x=3
⇒ 480(x−x+8)x(x−8)=3
⇒ 4803×8=x2–8x
⇒ 1280=x2–8x
⇒x2−8x−1280=0
⇒x2−40x+32x−1280=0
⇒x(x−40)+32(x−40)=0
⇒(x+32)(x−40)=0
Either x+32=0orx−40=0
As, speed cannot be in negative values,
hence , we get x=40
Thus the speed of the train is 40 kmph.