Question

a train travels a distance of 840 km at a uniform speed if the speed had been 6 km/h less, then it would have taken 2 hours more to cover the same distance. what is the speed of the train​

Answer 1

if the question is:-A car travels a distance of 840 kms at a uniform speed If the speed of the car is 10 kmph more it takes two hours less to cover the same distance The original speed of the car is

ANSWER

Let the original speed of car is x km \hr

Then time taken in moving 840 km=

x

840

hr

if speed is going 10 km \hr more =x+10

Then time taken in moving 840 km=

x+10

840

hr

∴

x

840

−

x+10

840

=2

⇒840(x+10)−840x=2x(x+10)

⇒2x

2

+20x−8400=0

⇒x

2

+70x+−60x−4200=0

⇒(x+70)(x−60)=0

⇒x=60orx=−70

If x=-70 is not true because speed not negetive

So speed is 60 km \ hr

hope this will help you