On a trip, a cyclist averaged 8 miles per hour for the first 12 miles and 12 miles per hour for the remaining 24 miles. If the cyclist returned immediately via the same route and took a total of 7.5 hours for the round trip, what was the average speed (in miles per hour) for the return trip?
Choose the correct choice from the following choices: A) 9 B) 10 C) 11 D) 12 E) 13
The time to go 36 miles was 12/8+24/12=1.5+2= 
<gadget id="calculator">1.5+2</gadget>
<output>3.5</output>
3.5 hours.   The average speed for the return trip was 36 miles/4 hours= 9 mph.   The answer is 9.
<result>A</result>
On a trip, a cyclist averaged 8 miles per hour for the first 12 miles and 12 miles per hour for the remaining 24 miles. If the cyclist returned immediately via the same route and took a total of 7.5 hours for the round trip, what was the average speed (in miles per hour) for the return trip?