Two men are standing on opposite ends of a 1000 metres long bridge. If they walk towards each other with speeds of 20 m/s and 5 m/s respectively, then how much time (in seconds) will they take to meet each other?

Options

A. 50
B. 30
C. 40
D. 60

Answer

To solve the problem, we need to determine how much time it will take for the two men to meet each other while walking towards each other on a 1000-meter long bridge.

### Step-by-Step Solution:

1. **Identify the speeds of the two men**:
- Speed of the first man (Man A) = 20 m/s
- Speed of the second man (Man B) = 5 m/s

2. **Calculate the combined speed**:
- Since they are walking towards each other, we can add their speeds to find the combined speed.
\[ \text{Combined Speed} = \text{Speed of Man A} + \text{Speed of Man B} = 20 \, \text{m/s} + 5 \, \text{m/s} = 25 \, \text{m/s} \]

3. **Determine the distance they need to cover**:
- The total distance between them is the length of the bridge, which is 1000 meters.

4. **Use the formula for time**:
- The formula to calculate time when distance and speed are known is:
\[ \text{Time} = \frac{\text{Distance}}{\text{Speed}} \]
- Plugging in the values:
\[ \text{Time} = \frac{1000 \, \text{meters}}{25 \, \text{m/s}} = 40 \, \text{seconds} \]

5. **Conclusion**:
- Therefore, the time taken for the two men to meet each other is **40 seconds**.