A truck moves at the speed of 90 km/hr after repairing and moves at the speed of 80 km/hr before repairing. It covers x distance in 8 hours after repairing. How much time (in hours) will it take to cover x distance before repairing?

Options

A. 8
B. 9
C. 10
D. 11

Answer

To solve the problem step by step, we will use the formula for distance, which is:

**Distance = Speed × Time**

### Step 1: Calculate the distance covered after repairing
The truck moves at a speed of 90 km/hr after repairing and covers a distance \( x \) in 8 hours. We can calculate the distance \( x \) using the formula:

\[ x = \text{Speed} \times \text{Time} \]

Substituting the values:

\[ x = 90 \, \text{km/hr} \times 8 \, \text{hours} \]

\[ x = 720 \, \text{km} \]

### Step 2: Calculate the time taken to cover the same distance before repairing
Now, we need to find out how much time it will take to cover the same distance \( x = 720 \, \text{km} \) before repairing when the truck moves at a speed of 80 km/hr. Again, we will use the distance formula rearranged to find time:

\[ \text{Time} = \frac{\text{Distance}}{\text{Speed}} \]

Substituting the values:

\[ \text{Time} = \frac{720 \, \text{km}}{80 \, \text{km/hr}} \]

\[ \text{Time} = 9 \, \text{hours} \]

### Final Answer
The time taken to cover the distance \( x \) before repairing is **9 hours**.

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