Question

A car driver travels from the plains to the hill station, which are 200 km apart, at an average speed of 40 km/h. In the return trip, he covers the same distance at an average speed of 20 km/h. The average speed of the car over the entire distance of 400 km is

• A. 16.56 km/h
• B. 17.89 km/h
• C. 26.67 km/h
• D. 35 km/h

Answer 1

Answer: (C)

26.67 km/h

Answer 2

Time duration when traveling at a speed of 40 km/h=$\frac{200}{40}$=5 hours
and time duration travelling at 20 km/h=$\frac{200}{20}=10$ hours
Total time=$10+5=15\space hours$
So, Average Speed = $\frac{400}{15}=26.67\space km/hr$
The correct option is (C): 26.67 km/h