From P and Q, two trains start moving towards each other at the same time. Their speeds are 120 km/h and 100 km/h, respectively. When the two trains meet each other, one train has covered 40 km more than the other train. Find the distance between P and Q?

Question: From P and Q, two trains start moving towards each other at the same time. Their speeds are 120 km/h and 100 km/h, respectively. When the two trains meet each other, one train has covered 40 km more than other train. Find the distance between P and Q?

Solution:
Speeds are in the ratio 120 : 100 = 6 : 5
So distances covered in the same time are also in the ratio 6 : 5

Let distances be 6k and 5k.

∴ Difference = 6k - 5k = 40
∴ k = 40

∴ Total distance = 6k + 5k = 11k = 11 × 40 = 440 km

So the distance between P and Q is 440 km.