A car traveled from town a to town b at the average speed of 24 miles per hour. the car then returned from town B to town A at the average speed of 48 miles per hour. What was the average speed of the car, on miles per hour, for the whole trip?

Question

A car traveled  from town a to town b at the average speed of 24 miles per hour. the car then returned from town B to town A at the average speed of 48 miles per hour. What was the average speed of the car, on miles per hour, for the whole trip?

anonymous · Answer

one thing for sure, it is not $\frac{24+48}{2}$

cwrw238 · Answer

its surprising how many people think that

anonymous · Answer

Thn

anonymous · Answer

lets call the distance between town A and B $m$ for miles, 
there will be no $m$ in the answer
since distance is rate times time, we know the time going was $\frac{m}{24}$ and the time returning was $\frac{m}{48}$ 
therefore the total time was 
$$\frac{m}{24}+\frac{m}{48}=\frac{2m}{48}+\frac{m}{48}=\frac{3m}{48}$$

anonymous · Answer

the total distance back and forth was $2m$ (since you went $m$ mile going, and $m$ miles returning

anonymous · Answer

so the average speed is total distance divided by total time, i.e. 
$$\frac{2m}{\frac{3m}{48}}$$ 
invert and multiply, cancel whatever you can (including the $m$ )and you will have your answer

anonymous · Answer

Please show me

anonymous · Answer

$$2m\times \frac{48}{3m}$$ is a start

anonymous · Answer

Is it 72  by anychance

anonymous · Answer

no

anonymous · Answer

32

anonymous · Answer

the $m$ cancels, so you get 
$$\frac{2\times 48}{3}$$ now divide 3 in to 48, multiply the result by 2

anonymous · Answer

yes