A car drove from Town A to Town B without stopping. The car traveled the first 80 miles of its journey at an average speed of 25 miles per hour. What was the car’s average speed, in miles per hour, for the remaining 80 miles if the car’s average speed for the entire trip was 40 miles per hour?	Choose the correct choice from the following.
A) 28	B) 48	C) 50	D) 55	E) 100
KAPLANOFFICIAL SOLUTION:   To solve this problem, you must remember that average speed means total distance divided by total time over an entire journey. This should not be confused with the average of the speeds. The total distance in this problem is 160 miles, but we will need to express the total time in a more complex way.   For the first 80 miles, the car traveled at 25 miles per hour. Therefore, we can say that the time this took was 80/25, because distance divided by rate equals time.   For the last 80 miles, we are trying to solve for the rate, so we can call this speed R. Thus, the time for the final 80 miles is 80/R.   If we put all of this together, knowing that the average speed over the entire journey is 40 miles per hour, we get the equation 160/(80/25 + 80/R) = 40. We can now solve for R and reach our answer.   160/(80/25 + 80/R) = 40   R = 100   100 is choice (100) and that’s our correct answer.
<result>E</result>
A car drove from Town A to Town B without stopping. The car traveled the first 80 miles of its journey at an average speed of 25 miles per hour. What was the car’s average speed, in miles per hour, for the remaining 80 miles if the car’s average speed for the entire trip was 40 miles per hour?