Myra drove at an average speed of 30 miles per hour for the first 30 miles of a trip & then at an average speed of 60 miles/hr for the remaining 30 miles of the trip. If she made no stops during the trip what was her average speed in miles/hr for the entire trip?	Pick:
A) The average speed is 35 miles per hour.
B) The average speed is 40 miles per hour.
C) The average speed is 55 miles per hour.
D) The average speed is 66 miles per hour.
E) The average speed is 45 miles per hour.
Here, distance for which Myra traveled at the two speeds is same.   Average Speed = 2ab/(a+b) = 2*30*60/(30 + 60)= 
<gadget id="calculator">2*30*60/(30 + 60)</gadget>
<output>40</output>
40 mph   Answer (The average speed is 40 miles per hour.)
<result>B</result>
Myra drove at an average speed of 30 miles per hour for the first 30 miles of a trip & then at an average speed of 60 miles/hr for the remaining 30 miles of the trip. If she made no stops during the trip what was her average speed in miles/hr for the entire trip?