An athlete runs 200 metres race in 24 seconds. His speed (in km/hr) is :

Options

A. 20
B. 24
C. 28.5
D. 30

Answer

To find the speed of the athlete in kilometers per hour, we can follow these steps:

### Step 1: Identify the given values
- Distance = 200 meters
- Time = 24 seconds

### Step 2: Calculate speed in meters per second
Speed is calculated using the formula:
\[ \text{Speed} = \frac{\text{Distance}}{\text{Time}} \]

Substituting the given values:
\[ \text{Speed} = \frac{200 \text{ meters}}{24 \text{ seconds}} \]

### Step 3: Simplify the fraction
Now, we simplify \( \frac{200}{24} \):
\[ \text{Speed} = \frac{200 \div 8}{24 \div 8} = \frac{25}{3} \text{ meters per second} \]

### Step 4: Convert speed to kilometers per hour
To convert meters per second to kilometers per hour, we use the conversion factor \( \frac{18}{5} \):
\[ \text{Speed in km/hr} = \text{Speed in m/s} \times \frac{18}{5} \]

Substituting the speed we calculated:
\[ \text{Speed in km/hr} = \frac{25}{3} \times \frac{18}{5} \]

### Step 5: Perform the multiplication
Calculating the right-hand side:
\[ \text{Speed in km/hr} = \frac{25 \times 18}{3 \times 5} = \frac{450}{15} = 30 \text{ km/hr} \]

### Final Answer
The speed of the athlete is **30 kilometers per hour**.

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