[問題]大全20-15

[davidslin]

大全-20-15.
In the United States, vacationers account for more than half of all visitors to what are technically called “pure aquariums” but for fewer than one quarter of all visitors to zoos, which usually include a “zoo aquarium” of relatively modest scope.

Which of the following, if true, most helps to account for the difference described above between visitors to zoos and visitors to pure aquariums?

(A) In cities that have both a zoo and a pure aquarium, local residents are twice as likely to visit the aquarium as they are to visit the zoo.
(B) Virtually all large metropolitan areas have zoos, whereas only a few large metropolitan areas have pure aquariums.
(C) Over the last ten years, newly constructed pure aquariums have outnumbered newly established zoos by a factor of two to one.
(D) People who visit a zoo in a given year are two times more likely to visit a pure aquarium that year than are people who do not visit a zoo.
(E) The zoo aquariums of zoos that are in the same city as a pure aquarium tend to be smaller than the aquariums of zoos that have no pure aquarium nearby.

答案給B
題目要解釋參觀純水族館跟參觀動物園裡的水族館的遊客比例上的差異
CDE都明顯不對
可是B說大城市都有動物園 而少數的城市才有水族館
是說因為稀少所以參觀的人才會多嘛?
如果是這樣解釋好像有點牽強 那也可以解釋說到處都有動物園 所以大家容易去參觀 所以參觀的人數比例會比較高 這說來 B就錯了呀
A的話說同時有水族館跟動物園時 當地人有兩倍的可能性去參觀水族館 好像還比較能解釋原題呀

煩請各位高手指點一下囉 謝謝

[Pufa]

度假者，
代表純水族館的遊客的50%，
同時也代表動物園遊客的25%（其中只有少數動物園有水族館）。

問怎麼會搞成這樣子？

B：
大城市都有動物園（所以方便去動物園的人多->分母變大，分子->度假者人數不變），
但只有少數大城市有純水族館（方便去純水族館的人少->分母小，分子->度假者人數不變）。


我發現CR不是難，是閱讀難.....唉。

[peche]

B 我還是有點想不通

(A) In cities that have both a zoo and a pure aquarium, local residents are twice as likely to visit the aquarium as they are to visit the zoo.
但A 不會對的原因 在於 local residents ~困擾題

[davidslin]

這裡的度假者 是指說[所有去水族館的遊客]與[所有去動物園的遊客]合計數中的度假者嗎?
例如[所有去水族館的遊客]有10人,[所有去動物園的遊客]有20人(假設沒有重複) 在那30人中,屬於度假者有的5人(其他人可能是當地遊客,不是去度假的,搞不好是校外教學之類)

應該是這意思吧.......?

[HCA]

A不是因為只是local resident而錯
畢竟local resident也可以是visitor

A錯的原因是因為削弱選項
local resident 去aqua是去zoo的兩倍

[dibert8]

(A) 題目講 vacationer 佔所有 aquarium 訪客的1/2,佔所有 zoo 訪客的1/4,當地居民喜歡去哪個不會導致 vacationer 的結果.
(B) 所以去度假的時候就比較會挑 aquarium 去啦! 所以 vacationer 去 aquarium 佔總訪客的人數就高過去 zoo 佔總訪客的人數.
(C) 新建 aquarium 和 zoo 的數量=2:1,分配下來,去 aquarium 人數的比例可能比去 zoo 低喔!
(D) 這麼說,去 aquarium 的總人數會是去 zoo 總人數的兩倍
(E) 跟 zoo 的大小無關