Gwen drove an average speed of 15 miles per hour for the first 40 miles of a tripthen at a average speed of 30 miles/hr for the remaining 40 miles of the trip if she made no stops during the trip what was Gwen's avg speed in miles/hr for the entire trip	Choices:
A) 35  B) 20  C) 45  D) 50  E) 55
Avg. speed = total distance / total time   Total distance = 80 miles   Total time = 40 / 15 + 40/30= 
<gadget id="calculator">40 / 15 + 40/30</gadget>
<output>4</output>
4   Avg. speed= 20.   Answer - 20
<result>B</result>
Gwen drove an average speed of 15 miles per hour for the first 40 miles of a tripthen at a average speed of 30 miles/hr for the remaining 40 miles of the trip if she made no stops during the trip what was Gwen's avg speed in miles/hr for the entire trip