Question

average speed for the round trip?A car travels from A to B at a speed of 40 mph then returns, using the same road, from B to A at a speed of 60 mph. What is the average speed for the round trip?A car travels from A to B at a speed of 40 mph then returns, using the same road, from B to A at a speed of 60 mph. What is the average speed for the round trip?A car travels from A to B at a speed of 40 mph then returns, using the same road, from B to A at a speed of 60 mph. What is the average speed for the round trip?

Answer 1

Average speed of round trip is 48 mph

Explanation:

Let the distance from A to B be s.

A car travels from A to B at a speed of 40 mph then returns, using the same road, from B to A at a speed of 60 mph.

$\texttt{Time taken to travel from A to B = }\frac{s}{40}\\\\\texttt{Time taken to travel from B to A = }\frac{s}{60}\\\\\texttt{Total time = }\frac{s}{40}+\frac{s}{60}\\\\\texttt{Total time = }\frac{60s+40s}{40\times 60}\\\\\texttt{Total time = }\frac{100s}{2400}\\\\\texttt{Total time = }\frac{s}{24}$

Total distance traveled = 2s

Total distance traveled = Average speed x Total time

$2s=\texttt{Average speed}\times \frac{s}{24}\\\\\texttt{Average speed = }48mph$

Average speed of round trip is 48 mph