Question

A train travels a distance of 300km at constant speed.If the speed of the train is increased by 5km an hour the journey would have to take 2hours less we need to find the original speed of the train

Answer 1

I hope it will help you.....

Answer 2

Answer:

Let the original speed of the train be y km / hr .

A.T.Q.

$\displaystyle{\frac{300}{y} -\frac{300}{y+5} =2 }$

300 ( y + 5 ) - 300 y = 2 y ( y + 5 )

y² + 5 y - 750 = 0

y² + 30 y - 25 y - 750 = 0

( y + 30 ( y -25 ) = 0

y = - 30 or y = 25

Since , speed of train can't be negative .

Therefore , the original speed of the train is 25 km / hr .