sat math question

[desi_chick]

<p>hi i don't get the following question, need explanations:</p>

<p>-A car traveled 10 miles at an average speed of 20mph and then traveled to the next 10 miles at an average speed of 40mph. What was the average speed in miles per hour of the car for the 20 miles?</p>

<p>Answer: 80/3</p>

<p>thnxs.</p>

[anhtimmy]

<p>Trip 1:
-10 miles
-20 mph
-time: .5h</p>

<p>Trip 2:
-10 miles
-40 mph
-time: .25h</p>

<p>total distance/total time
20/.75 -> convert to writable fraction -> 80/3</p>

<p>boonshakalaka?</p>