A train overtakes two persons who are walking in the same direction in which the train is going, at the rate of 2 kmph and 4 kmph and passes them completely in 9 and 10 seconds respectively. The length of the train is:

We are given:

• Speed of person A = 2 kmph, time taken = 9 sec
• Speed of person B = 4 kmph, time taken = 10 sec

Step 1: Let train speed = X km/h, length = L meters
Use formula: Relative speed (same direction) = Train speed − Person speed

(X − 2) × (5/18) = L / 9 (X − 4) × (5/18) = L / 10

Step 2: Solve both equations
From both: (5/2)(X − 2) = (25/9)(X − 4)
⇒ X = 22 km/h

Step 3: Plug X back to find L
L = (5/2)(22 − 2) = 50 meters

Final Answer:
The length of the train is 50 meters