A motorist travels for 3.0 h at 80 km/h and 2.0 h at 100 km/h.What is her average speed for the trip?

Question

Quizplus · Accepted Answer

To calculate average speed, we use the formula:
Average speed = Total distance / Total time

Let's assume the distance traveled is D.

The time taken to cover the first part of the journey at 80 km/h is 3 hours. Therefore, the distance covered in this part is 3 × 80 = 240 km.

The time taken to cover the second part of the journey at 100 km/h is 2 hours. Therefore, the distance covered in this part is 2 × 100 = 200 km.

Therefore, the total distance covered in the entire journey is D = 240 + 200 = 440 km.

The total time taken is 3 + 2 = 5 hours.

Therefore, the average speed is:
Average speed = Total distance / Total time
Average speed = 440 / 5
Average speed = 88 km/h

Hence, the answer is B, 88 km/h.

A Motorist Travels for 3