<PRE><B>Question 132812</B>
For the first 100 km of a 200-km trip, a student drove at a speed of 40 km/h. For the second half of the trip, the student drove at a speed of 60 km/h. What was the average speed for the entire trip?

       speed for the first half of the trip = 40km/hr.

       speed for the second half of the trip = 60km/hr.
  
       total speed for the entire trip =  40+60 km/hr
                                       = 100km/hr

         therefore aveg speed for the entire trip =  100/2 = 50km/hr</PRE>