[求助]求助GWD2-18

游魂

On a certain transaltatic 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 roung-trip tickets did not take their cars abroad the ship, what percent of the ship's passengers held round-trip tickets?

1) 33 1/3%

2) 40%

3) 50%

4) 60%

5) 66 2/3%

Please help!! thank you!!

sammen

(100%-60%)*R( passengers with round tickets)=20%*Total passengers

sammen

做这个题目最好画图,一画就明白了.