A freight train left Delhi for Mumbai at an average speed of 40 km/hr. Two hours later, an express train left Delhi for Mumbai, following the freight train on a parallel track at an average speed of 60 km/hr. How far from Delhi would the express train meet the freight train?

Explanation:

1. Calculate the distance covered by the freight train before the express train starts. The freight train travels for 2 hours at 40 km/hr. Distance = Speed * Time = 40 km/hr * 2 hr = 80 km. So, when the express train starts, the freight train is 80 km ahead.

2. Calculate the relative speed of the express train with respect to the freight train. Since both trains are moving in the same direction, the relative speed is the difference in their speeds. Relative Speed = Express Train Speed - Freight Train Speed = 60 km/hr - 40 km/hr = 20 km/hr.

3. Calculate the time it takes for the express train to catch up to the freight train. Time = Distance / Relative Speed = 80 km / 20 km/hr = 4 hours. The express train will travel for 4 hours until it meets the freight train.

4. Calculate the distance from Delhi where they meet. This distance is covered by the express train in the 4 hours it travels. Distance = Express Train Speed * Time = 60 km/hr * 4 hr = 240 km.

Therefore, the express train would meet the freight train 240 km from Delhi.

Analyzing the options: A) 480 km: Incorrect. This would imply a much longer travel time. B) 260 km: Incorrect. Does not align with the calculations. C) 240 km: Correct, as calculated above. D) 120 km: Incorrect. This would be the distance if the express train traveled for only 2 hours, but it needs to travel longer to catch up.

The final answer is C.