Rohit crosses a 700 metre wide road in 35 seconds. What is his speed (in km/hr)?

Options

A. 54
B. 76
C. 72
D. 84

Answer

To find Rohit's speed in kilometers per hour, we can follow these steps:

### Step 1: Identify the given values
- Distance = 700 meters
- Time = 35 seconds

### Step 2: Calculate speed in meters per second
Speed is calculated using the formula:
\[ \text{Speed} = \frac{\text{Distance}}{\text{Time}} \]
Substituting the values:
\[ \text{Speed} = \frac{700 \text{ meters}}{35 \text{ seconds}} = 20 \text{ meters/second} \]

### Step 3: Convert speed from meters per second to kilometers per hour
To convert meters per second to kilometers per hour, we use the conversion factor:
\[ 1 \text{ meter/second} = \frac{3600 \text{ seconds}}{1000 \text{ meters}} \text{ kilometers/hour} \]
Thus, we can convert:
\[ \text{Speed in km/hr} = 20 \text{ m/s} \times \frac{3600 \text{ seconds}}{1000 \text{ meters}} \]

### Step 4: Simplify the calculation
Calculating the above:
\[ \text{Speed in km/hr} = 20 \times \frac{3600}{1000} = 20 \times 3.6 = 72 \text{ km/hr} \]

### Final Answer
Rohit's speed is **72 km/hr**.

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