A train 150 m length crosses an electric pole In 5 s. How much time it will take to cross a bridge of 180 m length?

Options

A. 10 s
B. 11s
C. 20 s
D. 30 s

Answer

To solve the problem, we need to determine how long it will take for a train of 150 meters in length to cross a bridge of 180 meters in length. We will follow these steps:

### Step 1: Calculate the Speed of the Train
The train crosses an electric pole in 5 seconds. The length of the train is 150 meters.

To find the speed of the train, we use the formula:
\[ \text{Speed} = \frac{\text{Distance}}{\text{Time}} \]
Here, the distance is the length of the train (150 m) and the time is 5 seconds.

\[ \text{Speed} = \frac{150 \text{ m}}{5 \text{ s}} = 30 \text{ m/s} \]

### Step 2: Calculate the Total Distance to Cross the Bridge
When the train crosses the bridge, it needs to cover both its own length and the length of the bridge.

The total distance to be covered is:
\[ \text{Total Distance} = \text{Length of Train} + \text{Length of Bridge} = 150 \text{ m} + 180 \text{ m} = 330 \text{ m} \]

### Step 3: Calculate the Time to Cross the Bridge
Now that we have the speed of the train and the total distance to cross, we can find the time taken to cross the bridge using the formula:
\[ \text{Time} = \frac{\text{Distance}}{\text{Speed}} \]
Substituting the values we have:
\[ \text{Time} = \frac{330 \text{ m}}{30 \text{ m/s}} = 11 \text{ s} \]

### Conclusion
The time it will take for the train to cross the bridge is **11 seconds**.

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