Question

Andre and Kayla ride their bikes from their home to school, which is 8.4 kilometers away. It takes Andre 20 minutes to arrive at school, and Kayla arrives 5 minutes after Andre. How much faster is Andre's average speed for the entire trip?

A) Andre's average speed is 2 km/hr faster.
B) Andre's average speed is 4 km/hr faster.
C) Andre's average speed is 5 km/hr faster.
D) Andre's average speed is 6 km/hr faster.

Answer 1

Andre's average speed is 5.04 km/hr faster than Kayla's.

Step-by-step explanation:

To find the average speed, we need to calculate the total distance traveled by each person and divide it by the total time taken. Andre takes 20 minutes to travel 8.4 kilometers, so his average speed is 8.4 km / (20/60) min = 25.2 km/hr. Kayla arrives 5 minutes after Andre, so her total time taken is 20 + 5 = 25 minutes. The total distance traveled by Kayla is also 8.4 kilometers, so her average speed is 8.4 km / (25/60) min = 20.16 km/hr. Andre's average speed is 25.2 km/hr - 20.16 km/hr = 5.04 km/hr faster than Kayla's.