Question

A train travels a distance of 300kms at a constant speed. If the speed of the train is increased by 10km/ hour, the j ourney would have taken 1 hour less. Find the original speed of the train.

Answer 1

Let the speed of the train be S. 

D=300Km, Time = Distance/ Speed. Time difference= ! Hours 

Hence, in these two conditions,

`300/"S" - 300/("S" + 10) = 1`

⇒ 300 (S+ 10) - 3005= S (S+ 10) 

⇒ s² + 105 - 3000 = 0 

⇒ S² + 605 -505 - 3000 = 0 

⇒ S (S - 60) - 50 (S - 60) = 0 

⇒ (S + 60) (S - 50) = 0

As the speed can't be negative, S = 50 km/ hr .