In the first hour of a two-hour trip, a car traveled \(d\) kilometers, and in the second hour of the trip, the car trave

In the first hour of a two-hour trip, a car traveled \(d\) 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?

(A) \(d\)

(B) \(\dfrac13\cdot d\)

(C) \(\dfrac12\cdot d\)

(D) \(\dfrac34\cdot d\)

(E) \(\dfrac32\cdot d\)

Answer: D

Source: GMAT Paper Tests