Question Detail
A motorist travel to a place 150 km away at an avearge speed of 50 km/hr and returns ar 30 km/hr.His average speed for the whole jouney in km/hr is
- 36.5 km/hr
- 37.5 km/hr
- 35.5 km/hr
- 34.5 km/hr
Answer: Option B
Explanation:
Average speed will be
\begin{aligned}
\frac{2xy}{x+y} km/hr
= \frac{2(50)(30)}{50+30} km/hr
\end{aligned}
= 37.5 km/hr