Question

A car travels at the speed of 50 km/hr for the first half of the journey and at the speed of 60 km/hr for the second half of the journey. What is the average speed of the car for the entire journey?

• A. 54.54 km/hr
• B. 36.36 km/hr
• C. 50.5 km/hr
• D. 45.45 km/hr

Answer 1

Answer:

A. 54.54 km/hr

Let the Distance = 2D

$\frac{D}{50}+\frac{D}{60}=Total time$

Average Speed$=\frac{2D}{\frac{D}{50}+\frac{D}{60}}$

$=\frac{2\times50\times60}{110}$

$=\frac{600}{11}$

$=54.54km/hr$