An athlete runs 400 meters race in 25 seconds. His speed (in km/hr) is

Options

A. (A) 57.6 km/hr
B. (B) 133 km/hr
C. (C) 16 km/hr
D. (D) 127 km/hr

Answer

To find the speed of the athlete in kilometers per hour (km/hr), we can follow these steps:

### Step 1: Identify the distance and time
- The athlete runs a distance of 400 meters in a time of 25 seconds.

### Step 2: Convert the distance from meters to kilometers
- Since 1 kilometer = 1000 meters, we convert 400 meters to kilometers:
\[ \text{Distance in kilometers} = \frac{400 \text{ meters}}{1000} = 0.4 \text{ km} \]

### Step 3: Convert the time from seconds to hours
- Since 1 hour = 3600 seconds, we convert 25 seconds to hours:
\[ \text{Time in hours} = \frac{25 \text{ seconds}}{3600} = \frac{25}{3600} \text{ hours} \]

### Step 4: Calculate the speed using the formula
- The formula for speed is:
\[ \text{Speed} = \frac{\text{Distance}}{\text{Time}} \]
- Substituting the values we have:
\[ \text{Speed} = \frac{0.4 \text{ km}}{\frac{25}{3600} \text{ hours}} = 0.4 \text{ km} \times \frac{3600}{25} \]

### Step 5: Simplify the calculation
- Now, calculate:
\[ \text{Speed} = 0.4 \times \frac{3600}{25} \]
\[ = 0.4 \times 144 = 57.6 \text{ km/hr} \]

### Final Answer
- The speed of the athlete is **57.6 km/hr**.

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