The ratio of speeds of two aeroplanes is 11 : 18. If the first aeroplane covers a distance of 1650 Km is 3 hours, then what is the speed (in m/s) of the aeroplane ?

Options

A. 225
B. 200
C. 270
D. 250

Answer

To find the speed of the first aeroplane in meters per second, we can follow these steps:

### Step 1: Calculate the speed of the first aeroplane in km/h
We know that:
- Distance = 1650 km
- Time = 3 hours

Using the formula:
\[ \text{Speed} = \frac{\text{Distance}}{\text{Time}} \]

Substituting the values:
\[ \text{Speed} = \frac{1650 \text{ km}}{3 \text{ hours}} = 550 \text{ km/h} \]

### Step 2: Convert the speed from km/h to m/s
To convert km/h to m/s, we use the conversion factor:
\[ 1 \text{ km/h} = \frac{1000 \text{ meters}}{3600 \text{ seconds}} = \frac{1}{3.6} \text{ m/s} \]

Now, converting 550 km/h to m/s:
\[ \text{Speed in m/s} = 550 \times \frac{1}{3.6} \]

Calculating this:
\[ \text{Speed in m/s} = \frac{550}{3.6} \approx 152.78 \text{ m/s} \]

### Step 3: Round the speed to the nearest whole number
Since speed is often expressed as a whole number, we can round 152.78 m/s to 153 m/s.

### Final Answer
The speed of the first aeroplane is approximately **153 m/s**.

---