Question

A train travels 480km at a uniform speed . if the speed had been 10km/h more, it would have taken 4hours less for the same journey , find the speed of the train
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Answer 1

Answer:

Step-by-step explanation:

Let the speed of the train be x km/hr. Then

Time taken to travel a distance of 480km=  

x

480

​  

hr

Time taken by the train to travel a distance of 480km with the speed (x−8)km/hr=  

x−8

480

​  

hr

It is given that if the speed had been 8km/hr less, then the train would have taken 3 hours more to cover the same distance

∴  

x−8

480

​  

=  

x

480

​  

+3

⇒  

x−8

480

​  

−  

x

480

​  

=3⇒  

x(x−8)

480(x−x+8)

​  

=3⇒  

x(x−8)

480×8

​  

=3

⇒3x(x−8)=480×8⇒x(x−8)=160×8⇒x  

2

−8x−1280=0

This is the required quadratic equation.