2016 · Q99
A motorist travels to a place 150 km away at an average speed of 50 km/hour and returns at 30 km/hour. What is the average speed for the whole journey ?
Elementary MathematicsTime, Speed and Distance
- A35 km/hour
- B37 km/hour
- C37.5 km/hour
- D40 km/hour
Explanation
Total distance is 300 km and total time is 150/50+150/30 = 3+5 = 8 h. Average speed = 300/8 = 37.5 km/h. Hence option C.