Question

Two trains travelling along parallel tracks in the same direction do 50 km/h and 100 km/h on average. The faster train starts 2 hours later than the slower. After how many kilometres will the faster train catch up?​

Answer 1

• 200 km

Explanation:

Let the faster train catches the slower one after x hours.

The distance the trains travel is same:

• 50(x + 2) = 100x
• 50x + 100 = 100x
• 50x = 100
• x = 2

The distance is:

• 50*(2 + 2) = 100*2 = 200 km