求GWD一道

题目没看明白,望高手解答,在线等,谢谢.

On a certain transatlantic crossing, 20 percent of a ship’s passengers held round-trip tickets and also took their cars abroad the ship.  If 60 percent of the passengers with round-trip tickets did not take their cars abroad the ship, what percent of the ship’s passengers held round-trip tickets?

A.     33 1/3%

B.     40%

C.     50%

D.     60%

E.      66 2/3%