In the first hour of a two-hour trip, a car traveled 3d kilometers, and in the second hour of the trip, the car traveled one-half that distance. What is the average rate at which the car traveled during the trip, in kilometers per hour?
Choose the correct choice from the following answers
A) d B) 1/3*d C) 1/2*d D) 5/4*d E) 3/2*d
Solution:   Lets look at the information given in the question...   Total time travelled = 2 hrs   Distance travelled first hour = 3d   Distance travelled second hour = 3d/2   The question is asking for the avg speed at which the car travels for 2 hrs   We know that avg speed = total distance/total time   Lets place the information given in the question to the formula above = (d+3d/2)/2   = 5/4*d   We find that option D is the answer as it gives the same expression as found in our calculation above. Answer option 5/4*d.
<result>D</result>
In the first hour of a two-hour trip, a car traveled 3d kilometers, and in the second hour of the trip, the car traveled one-half that distance. What is the average rate at which the car traveled during the trip, in kilometers per hour?