To determine the average speed of the car during its trip, we can use the formula for average speed, which is defined as the total distance traveled divided by the total time taken. ### Step-by-Step Explanation: 1. **Identify the Total Distance**: The car travels a total distance of 120 kilometers. 2. **Identify the Total Time**: The time taken for this journey is 2 hours. 3. **Use the Average Speed Formula**: The formula for average speed (v) is given by: \[ v = \frac{\text{Total Distance}}{\text{Total Time}} \] 4. **Substitute the Values**: Plugging in the values we have: \[ v = \frac{120 \text{ km}}{2 \text{ hours}} \] 5. **Perform the Calculation**: Now, we perform the division: \[ v = 60 \text{ km/h} \] Thus, the average speed of the car during its trip is **60 km/h**. ### Why Option B is Correct: - The calculation shows that the average speed is 60 km/h, which matches option B. This is the correct answer because it accurately reflects the relationship between distance and time. ### Why the Other Options are Incorrect: - **Option A (30 km/h)**: This would imply that the car traveled only 60 kilometers in 2 hours, which is incorrect since the distance is 120 kilometers. - **Option C (90 km/h)**: This would suggest that the car covered 180 kilometers in 2 hours, which is also incorrect as the distance is only 120 kilometers. - **Option D (120 km/h)**: This would mean the car traveled 240 kilometers in 2 hours, which is not possible given the actual distance of 120 kilometers. ### Common Pitfalls: - **Misunderstanding Average Speed**: Some students might confuse average speed with instantaneous speed, which can vary during the trip. Average speed is a simple calculation based on total distance and total time. - **Incorrect Division**: Ensure that the division is performed correctly. A common mistake could be miscalculating the division, leading to an incorrect average speed. ### Revision Summary: - Average speed is calculated using the formula: \( v = \frac{\text{Total Distance}}{\text{Total Time}} \). - For this problem, the total distance is 120 km and the total time is 2 hours. - The average speed is 60 km/h, which corresponds to option B. - Always double-check calculations to avoid common errors in division.