In traveling from a dormitory to a certain city, a student went 1/2 of the way by foot, 3/5 of the way by bus, and the remaining 4 kilometers by car. What is the distance, in kilometers, from the dormitory to the city?  Pick.
A) 20
B) 15
C) 40
D) 10
E) 12
Whole trip = distance by foot + distance by bus + distance by car   x = 1/2x + 3/5x + 4   x - 1/2x - 3/5x = 4   x=20km   Option: 20
<result>A</result>
In traveling from a dormitory to a certain city, a student went 1/2 of the way by foot, 3/5 of the way by bus, and the remaining 4 kilometers by car. What is the distance, in kilometers, from the dormitory to the city?