If a man running at 15 kmph crosses a bridge in 5 minutes, the length of the bridge is

Options

A. 1000 metres
B. 500 metres
C. 750 metres
D. 1250 metres

Answer

To find the length of the bridge that a man crosses while running at a speed of 15 km/h in 5 minutes, we can follow these steps:

### Step 1: Convert the time from minutes to hours
Since the speed is given in kilometers per hour (km/h), we need to convert the time from minutes to hours.

\[ \text{Time in hours} = \frac{5 \text{ minutes}}{60} = \frac{1}{12} \text{ hours} \]

**Hint:** To convert minutes to hours, divide the number of minutes by 60.

### Step 2: Use the formula for distance
The formula to calculate distance is:

\[ \text{Distance} = \text{Speed} \times \text{Time} \]

### Step 3: Substitute the values into the formula
We know the speed is 15 km/h and the time is \(\frac{1}{12}\) hours. Now we can substitute these values into the formula:

\[ \text{Distance} = 15 \text{ km/h} \times \frac{1}{12} \text{ hours} \]

### Step 4: Calculate the distance
Now we perform the multiplication:

\[ \text{Distance} = 15 \times \frac{1}{12} = \frac{15}{12} = \frac{5}{4} \text{ km} \]

### Step 5: Convert the distance from kilometers to meters
Since the options are in meters, we need to convert kilometers to meters. We know that 1 km = 1000 meters.

\[ \text{Distance in meters} = \frac{5}{4} \text{ km} \times 1000 \text{ m/km} = \frac{5 \times 1000}{4} = \frac{5000}{4} = 1250 \text{ meters} \]

### Conclusion
The length of the bridge is **1250 meters**.

**Final Answer:** 1250 meters

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