A 180 - metre long train crosses a man standing on the platform in 6 seconds. What is the speed of the train?

Options

A. 90 km/hr
B. 108 km/hr
C. 120 km/hr
D. 88 km/hr

Answer

To find the speed of the train that crosses a man standing on the platform, we can follow these steps:

### Step-by-Step Solution:

1. **Identify the Length of the Train and Time Taken**:
- The length of the train is given as 180 meters.
- The time taken to cross the man is 6 seconds.

2. **Use the Formula for Speed**:
- The formula for speed is:
\[ \text{Speed} = \frac{\text{Distance}}{\text{Time}} \]
- Here, the distance is the length of the train (180 meters) and the time is 6 seconds.

3. **Calculate the Speed in Meters per Second**:
- Substitute the values into the formula:
\[ \text{Speed} = \frac{180 \text{ meters}}{6 \text{ seconds}} = 30 \text{ meters per second} \]

4. **Convert Speed to Kilometers per Hour**:
- To convert from meters per second to kilometers per hour, use the conversion factor:
\[ 1 \text{ meter per second} = 3.6 \text{ kilometers per hour} \]
- Therefore, to convert 30 meters per second to kilometers per hour:
\[ \text{Speed in km/h} = 30 \text{ m/s} \times 3.6 = 108 \text{ km/h} \]

5. **Final Answer**:
- The speed of the train is **108 kilometers per hour**.