标题: GWD31-15一道数学求助~~~ [打印本页] 作者: dolorez 时间: 2009-12-10 22:26 标题: GWD31-15一道数学求助~~~ On a certin transatlantic crossing,20 percent of a ship's passengers held round-trip tickets and also took their cars broad the ship.If 60 percent of the passengerswith round-trip tickets did not take their cars abroad the ship,what percent of the ship's passengers held round-trip tickets? A.20% B 30% c.50% D60% E 60%作者: genius_fang 时间: 2009-12-10 23:12
选C吧~说乘客总人数中20%有r-t并且 took their cars broad ，然后又r-t的人里面60%没有 took their cars broad ，言下之意，有r-t的人里面40% took their cars broad 。所以设总人数x，有r-t的y，40%y=20%x算出来y占50%作者: nicolewitch 时间: 2009-12-15 18:16
我觉得这个题有问题啊,你不可以assume那两个took cards的量是相等的哎,因为20 percent of a ship's passengers held round-trip tickets and also took their cars broad the ship,那如果没有round-trip T的人里也有take cads的呢,是我理解的太复杂了还是题干本身就有点问题啊,不知道LZ怎么个理解法。。。我老是把问题复杂化,哎