A car travels the first 1 / 3 of the distance at 60 km/h, the next 1 / 3 at 40 km/h, and the last 1 / 3 at 80 km/h. What is the average speed for the entire trip?
Q1. A car travels the first 1 / 3 of the distance at 60 km/h, the next 1 / 3 at 40 km/h, and the last 1 / 3 at 80 km/h. What is the average speed for the entire trip?
Answer: 54.55 km/h
Explanation: Let total distance = d. Time taken for first 1 / 3 = (d / 3) / 60 = d / 180. For second 1 / 3 = (d / 3) / 40 = d / 120.