Question

A man travels 40 km at speed 20 km/h and next 60 km at 30 km/h and there after travel 80 km at 40 km/h. His average speed is

• A. 30 km/h
• B. 25 km/h
• C. 20 km/h
• D. 15 km/h

Answer 1

Answer:

A. 30 km/h

Time taken for the first 40 km = 40/20 = 2 h Time taken for the next 60 km = 60/30 = 2 h Time taken for the next 80 km = 80/40 = 2 h Total time = 2 + 2 + 2 = 6 h Total distance = 40 + 60 + 80 = 180 km Average speed = Total distance/Total time = 180/6 = 30 km/h