City A to city B, Andrew drove for 1hr at 40 mph and for 3 hours at 60 mph. What was the average speed for the whole trip? Choose the correct choice from the following options.
A) 55  B) 57.5  C) 61  D) 61.5  E) 62.5
The total distance is 1×40+3×60=220   And the total time is 4 hours. Hence,   55verage Speed=(Total Distance/Total Time)   =220/4= 
<gadget id="calculator">220/4</gadget>
<output>55</output>
55   55
<result>A</result>
City A to city B, Andrew drove for 1hr at 40 mph and for 3 hours at 60 mph. What was the average speed for the whole trip?