To determine which car has a higher average speed over the whole journey, we’ll use the formula for average speed:

$\text{Average Speed} = \frac{\text{Total Distance}}{\text{Total Time}}$

Step 1: Determine the Total Distance

Since both cars are traveling from City X to City Y, they each travel a total distance of 60 km.

Step 2: Calculate the Total Time for Each Car

• Car A starts at 11:00 and finishes at 12:45, which is a total time of: $12:45 - 11:00 = 1 \text{ hour and } 45 \text{ minutes} = 1.75 \text{ hours}$

• Car B starts at 12:15 and finishes at 13:30, which is a total time of: $13:30 - 12:15 = 1 \text{ hour and } 15 \text{ minutes} = 1.25 \text{ hours}$

Step 3: Calculate the Average Speed for Each Car

1. Average Speed of Car A: $\text{Average Speed of Car A} = \frac{60 \text{ km}}{1.75 \text{ hours}} \approx 34.29 \text{ km/h}$

2. Average Speed of Car B: $\text{Average Speed of Car B} = \frac{60 \text{ km}}{1.25 \text{ hours}} = 48 \text{ km/h}$

Conclusion

Since Car B has an average speed of 48 km/h compared to Car A's 34.29 km/h, Car B has the higher average speed during the whole journey.

Would you like more details on average speed calculations or further analysis?

Here are five questions for further exploration:

1. How would the answer change if the distance were different?
2. What factors could affect the accuracy of this average speed calculation?
3. How can we calculate the instantaneous speed at any point on the journey?
4. How would we calculate the total time if there were a rest stop involved?
5. What if one of the cars took a different route? How would that affect the average speed?

Tip: Average speed depends solely on total distance and total time, not on the path taken, making it ideal for evaluating direct journeys.