Mirun travels the first 3 hours of her journey at 20 mph speed and the remaining 2 hours at 40 mph speed. What is the average speed of Mirun 's travel in mph?
Choose the correct choice from the following choices
A) 26mph	B) 27mph	C) 22mph	D) 28mph	E) 23mph
Explanation :   Average speed=Total Distance/Time.   Total distance travelled by Mirun = Distance covered in the first 3 hours + Distance covered in the next 2 hours.   Distance covered in the first 3 hours = 3Ã—20=60 miles   Distance covered in the next 2 hours= 2Ã—40=80 miles   Therefore, total distance travelled = 60+80= 
<gadget id="calculator">60+80</gadget>
<output>140</output>
140 miles.   The total time taken= 3+2= 
<gadget id="calculator">3+2</gadget>
<output>5</output>
5hours.   Hence, the average speed=140/5= 
<gadget id="calculator">140/5</gadget>
<output>28</output>
28mph.   Answer : 28mph
<result>D</result>
Mirun travels the first 3 hours of her journey at 20 mph speed and the remaining 2 hours at 40 mph speed. What is the average speed of Mirun 's travel in mph?