Question

Bob rides a bike to school. Within the first 10 minutes, his average speed is 4 m/s, and he speeds up after that. His average speed becomes 6 m/s, and he arrived at school in another 20 minutes. What is his average speed in meters per minute for the trip?

A. 200 m/min

B. 180 m/min

C. 150 m/min

D. 120 m/min

Answer 1

The average speed of Bob's trip is 5 meters per minute.

Step-by-step explanation:

To find the average speed of Bob's trip, we need to calculate the total distance he traveled and divide it by the total time taken. In the first 10 minutes, he traveled a distance of 4 m/s * 10 min = 40 meters. After that, he traveled for another 20 minutes at a speed of 6 m/s, covering a distance of 6 m/s * 20 min = 120 meters. The total distance covered is 40 meters + 120 meters = 160 meters. The total time taken is 10 min + 20 min = 30 minutes. Therefore, the average speed for the trip is 160 meters / 30 minutes = 5.33 meters per minute. Rounding to the nearest whole number, the average speed is approximately 5 meters per minute.