Question

A train running at the speed of 90 km/h crosses a 400 m long tunnel in 40 seconds. What is the length of the train (in meters)?

• A. 400
• B. 600
• C. 500
• D. 550

Hint:

Convert speed into meters per second before using distance = speed × time. Total distance is train length plus tunnel length.

Answer 1

The Correct Option is B

Speed of train = 90 km/h = 90 × \frac{1000}{3600} = 25 m/s.
Time taken to cross tunnel = 40 s.
Let the length of the train be L meters. The train covers the length of the tunnel plus its own length while crossing.
Total distance covered = 400 + L meters.
Using formula:
\[\text{Distance} = \text{Speed} \times \text{Time}\]
\[400 + L = 25 \times 40 = 1000 \text{ meters}\]
\[L = 1000 - 400 = 600 \text{ meters}\]