A car , running at `45 "km/hr"` takes `6` hours to cover a journey . At what speed must it travel to complete the journey in `5` hours ?

Options

A. `24 "km/hr".`
B. `53 "km/hr".`
C. `54 "km/hr".`
D. `50 "km/hr".`

Answer

To solve the problem step by step, we will follow the given information and apply the formulas for speed, distance, and time.

### Step-by-Step Solution:

1. **Identify the Given Information:**
- Speed of the car = 45 km/hr
- Time taken to cover the journey = 6 hours

2. **Calculate the Distance:**
- We use the formula for distance:
\[ \text{Distance} = \text{Speed} \times \text{Time} \]
- Substituting the values:
\[ \text{Distance} = 45 \, \text{km/hr} \times 6 \, \text{hours} = 270 \, \text{km} \]

3. **Determine the Required Speed for a 5-hour Journey:**
- We need to find the speed required to cover the same distance (270 km) in 5 hours.
- We use the formula for speed:
\[ \text{Speed} = \frac{\text{Distance}}{\text{Time}} \]
- Substituting the values:
\[ \text{Speed} = \frac{270 \, \text{km}}{5 \, \text{hours}} = 54 \, \text{km/hr} \]

4. **Conclusion:**
- The speed at which the car must travel to complete the journey in 5 hours is **54 km/hr**.