A train covered a certain distance at a uniform speed. If the train would have been 6km/hr faster, it would have taken 4hours less than the scheduled time. And if the train were slower by 6km/hr, it would have taken 6 hours more than the scheduled time. Find the distance of the journey.
Ans: Let the speed of the train by x km/hr
And the time taken by it by y
Now distance traveled by it is x x y = xy
APQ:
I--- (x + 6) (y - 4) = xy
4x - 6y = -24
=> 2x - 3y = -12 ----------------(1) II--- (x - 6) (y+ 6) = xy
6x - 6y= 36
=> x- y= 6 ----------------(2) Solving for x and y we get y = 24, x = 30
So the distance =30 × 24
= 720 km