In a 100m race, Kamal defeats Bimal by 5 seconds. If the speed of Kamal is 18 kmph, then the speed of Bimal is

Options

A. 15.4 kmph
B. 14.5 kmph
C. 14.4 kmph
D. 14 kmph

Answer

To solve the problem step by step, we can follow these instructions:

### Step 1: Understand the given information
- Kamal defeats Bimal by 5 seconds in a 100m race.
- Kamal's speed is given as 18 km/h.

### Step 2: Convert Kamal's speed from km/h to m/s
To convert km/h to m/s, we use the conversion factor \( \frac{5}{18} \):
\[ \text{Speed of Kamal in m/s} = 18 \times \frac{5}{18} = 5 \text{ m/s} \]

### Step 3: Calculate the time taken by Kamal to finish the race
Using the formula:
\[ \text{Time} = \frac{\text{Distance}}{\text{Speed}} \]
Kamal covers 100 meters at a speed of 5 m/s:
\[ \text{Time taken by Kamal} = \frac{100 \text{ m}}{5 \text{ m/s}} = 20 \text{ seconds} \]

### Step 4: Determine the time taken by Bimal
Since Kamal defeats Bimal by 5 seconds, Bimal's time to finish the race is:
\[ \text{Time taken by Bimal} = \text{Time taken by Kamal} + 5 \text{ seconds} = 20 \text{ seconds} + 5 \text{ seconds} = 25 \text{ seconds} \]

### Step 5: Calculate Bimal's speed
Using the formula for speed:
\[ \text{Speed} = \frac{\text{Distance}}{\text{Time}} \]
Bimal covers 100 meters in 25 seconds:
\[ \text{Speed of Bimal} = \frac{100 \text{ m}}{25 \text{ seconds}} = 4 \text{ m/s} \]

### Step 6: Convert Bimal's speed from m/s to km/h
To convert m/s to km/h, we use the conversion factor \( \frac{18}{5} \):
\[ \text{Speed of Bimal in km/h} = 4 \text{ m/s} \times \frac{18}{5} = \frac{72}{5} = 14.4 \text{ km/h} \]

### Final Answer
The speed of Bimal is **14.4 km/h**.

---