A man traveled a total distance of 900 km. He traveled one-third of the whole trip by plane and the distance traveled by train is one-half of the distance traveled by bus. If he traveled by train, plane and bus, how many kilometers did he travel by bus?
Choose the correct choice from the following choices.
A) 400 km	B) 450 km	C) 500 km	D) 550 km	E) 600 km
total distance traveled = 900 km.   distance traveled by plane = 300 km.   distance traveled by bus = x   distance traveled by train = x/2   x + x/2 + 300 = 900   3x/2 = 600   x = 400 km   The answer is 400 km.
<result>A</result>
A man traveled a total distance of 900 km. He traveled one-third of the whole trip by plane and the distance traveled by train is one-half of the distance traveled by bus. If he traveled by train, plane and bus, how many kilometers did he travel by bus?