Question

A train travelling at 36 kmph crosses a platform in 20 seconds and a man standing on the platform in 10 seconds. What is the length of the platform in meters?

• A. 240 meters
• B. 100 meters
• C. 200 meters
• D. 300 meters

Answer 1

The Correct Option is B

To solve the problem of finding the length of the platform, follow these steps: First, convert the train's speed from km/h to m/s. The formula for conversion is:
$$\text{Speed (m/s)} = \left(\frac{\text{Speed (km/h)}}{3.6}\right)$$
Substituting the given speed:
$$\text{Speed (m/s)} = \left(\frac{36}{3.6}\right) = 10 \text{ m/s}$$
Next, use the formula for distance traveled, which is:
$$\text{Distance} = \text{Speed} \times \text{Time}$$
Calculate the train's length using the time it takes to pass the man:
$$\text{Length of Train} = 10 \times 10 = 100 \text{ meters}$$
Find the total distance covered, crossing the platform and the man:
$$\text{Total Distance} = 10 \times 20 = 200 \text{ meters}$$
Finally, determine the platform's length by subtracting the train's length from the total distance:
$$\text{Length of Platform} = 200 - 100 = 100 \text{ meters}$$
Thus, the length of the platform is 100 meters.