Question

A train travels 360km at a uniform speed. if the speed had been 5km/h more it would have taken 1 hour less for the same journey. Find the speed of the train ?​

Answer 1

Answer:

Consider the given question,

Distance =360 km

Speed =x km/hr

When speed is increase (x+5) km/hr

Given expression is written as,

⇒ 360÷x − 360÷(x-5) =1

⇒ x+5−x÷x(x+5) = 1÷360

⇒x2 +5x=1800

⇒x 2+5x−1800=0

⇒x 2 +45x−40x−1800=0

⇒x(x+45)−40(x+45)=0

⇒(x+45)(x−40)=0

⇒x=40,−45

But, speed can not be negative.

Hence, speed is 40 km/hr

Answer 2

Step-by-step explanation:

let the original speed of the train be x km/ h

time taken to cover a distance of 360 km = 360/ x hour

new speed of the train ( x+5) km/ h

time taken to cover a distance of 360 km at new speed = 360 / x+5 hours

therofore. 360 / x +5 = 1

=> 360 ( x+5-x)/x ( x+5)= 1

360( s) =x²+5x

1800= x²+5x

x²+5x-1800= 0

x²+45x-40x-1800=0

x(x+45) ( x-40)=0

x=(-45) ,40

but since speed cannot be in negative

therefore. , x= 40 km / hr