CBSE Class 10 Answered

The time difference between the two cases is 2 hrs.

Train with  less speed naturally will take more time than the train with less speed.

Let the original speed be x km/ph

So using the formula,

 speed = distance/time

we get

 time taken by the slow train,]

=300/x

Time taken by the faster train

=300/(x+5)

So,

 acc to question,

Time taken by the slow train - time taken by the faster train = 2

300/x-300/(x+5)=2

300[1/x-1/(x+5)]=2

150[1/x-1/(x+5)]=1

150*5=x(x+5)

factorising,

 we get,

(x+30)(x-25)=0

x=25km/ph