Question

a passenger train takes 2 hours less for a journey of 300 km if the speed is increased by 5 km per hour from its usual speed find the usual speed of the train

Answer 1

yo

let the usual time taken be x
usual speed = 300/x

now, if 300/x+5 =x-2

300+5x=x^2-2x

x^2-7x-300=0 find value of x by factorisation
24.5 aprox

Answer 2

Answer:

Let the usual 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 usual speed of the train is 25 km / hr .