A train is moving at the speed of 54 km/hr. How many seconds it will take to cover a distance of 450 metres?

Options

A. 60
B. 30
C. 45
D. 36

Answer

To solve the problem of how many seconds it will take for a train moving at a speed of 54 km/hr to cover a distance of 450 meters, we can follow these steps:

### Step 1: Convert the speed from km/hr to m/s
The speed given is 54 km/hr. To convert this to meters per second (m/s), we use the conversion factor:
\[ \text{Speed in m/s} = \text{Speed in km/hr} \times \frac{5}{18} \]
Substituting the value:
\[ \text{Speed in m/s} = 54 \times \frac{5}{18} \]
Calculating this gives:
\[ \text{Speed in m/s} = 54 \times \frac{5}{18} = 54 \div 18 \times 5 = 3 \times 5 = 15 \text{ m/s} \]

### Step 2: Use the formula for time
We know the formula relating distance, speed, and time:
\[ \text{Distance} = \text{Speed} \times \text{Time} \]
We can rearrange this formula to solve for time:
\[ \text{Time} = \frac{\text{Distance}}{\text{Speed}} \]

### Step 3: Substitute the known values
We have the distance as 450 meters and the speed as 15 m/s. Substituting these values into the formula gives:
\[ \text{Time} = \frac{450 \text{ m}}{15 \text{ m/s}} \]

### Step 4: Calculate the time
Now, we perform the division:
\[ \text{Time} = 30 \text{ seconds} \]

### Conclusion
The train will take **30 seconds** to cover a distance of 450 meters.

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