+11912 distance between two stations is 340km . two trains start simuntaneously from these stations on parallel tracks to cross each other . the speed of one train is greater than the other by 5km per hour . if the distance between the two trains after two hours of their start is 30km , find the speed of each train ?
+128475 Ok.........the total distance traveled by both trains is 340km - 30 km = 310km
Let the speed of the slower train be x
So the speed of the faster train is x + 5
So the rate of the first train (x) times the time it has traveled (2 hrs) = some distance
And the rate of the second train (x+5) times the time it has traveled (2 hrs) = some distance
And the distances combined is 310km
So
x(2) + (x+5)(2) = 310
2x + 2x + 10 = 310 Subtract 10 from both sides
4x = 300 Divide by 4
x = 75km/hr And that's the rate of the slower train
And the faster train is traveling 5km/hr faster = 80km/hr
+33616 Start by letting the speed of the slower train be s km/hr. The speed of the other train is therefore s + 5 km/hr
Their relative speed (that is the speed of one as seen by the other) is the sum of these two; namely: 2s + 5 km/hr.
After two hours they will have travelled closer to each other by a distance (2s + 5)*2 km (because distance = speed*time). Since they started 340km apart and are now only 30km apart, the combined distance they have travelled is 340 - 30 = 310 km. So, we must have:
(2s + 5)*2 = 310
2s + 5 = 155
2s = 150
s = 75 km/hr
And the faster train's speed is 75+ 5 = 80 km/hr
(Edited to correct silly mistake!)
