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 ?
Answers
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
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