Question

A train travels a distance of 300 km at a constant speed .If
the speed of the train increased by 5 km,the journey would have taken 2 hours less.
Find the original speed of the train​

Answer 1

Answer:

et x km/hr be the constant speed of the train,

Then Time taken to cover 300km=  

x

300

​  

hrs

Time taken to cover 300km when the speed is increased by 5km/hr=  

x+5

300

​  

hours

It is given that the time to cover 300km is reduced by 2 hours

∴  

x

300

​  

−  

x+5

300

​  

=2

⇒  

x(x+5)

300(x+5)−300x

​  

=2⇒2x  

2

+10x=1500

⇒x  

2

+5x−750=0⇒x  

2

+30x−25x−750=0

⇒(x+30)(x−25)=0⇒x=25orx=−30

But x cannot be negative. Therefore x=25

Hence, the original speed of the train is 25km/hr