[求助]PP-T1-DS185

emma-maple

185. 17987-!-item-!-187;#058&011677
Of the 200 members of a certain association, each member who speaks German also speaks English, and 70 of the members speak only Spanish. If no member speaks all three languages, how many of the members speak two of the three languages?

(1) 60 of the members speak only English.

(2) 20 of the members do not speak any of the three languages.

Ans:C

不知道那位大大知道 三種交集的題目怎麼算

emma-maple

Of the 200 members of a certain association, each member who speaks

German also speaks English,

依照你的式子,第一句話的意思,是全部只有兩百個人的意思嗎?

我以為是機構中其中的200個人講German也講英文,因此我們不曉得全部有多少人,也就無

法算出只講兩種語言的人

oldmonkeyxu

分四种状态：会三种，只会两种，只会一种，任何一种都不会

题目说：200人，会德语的同时会英语（没有只会德语的），70个只会西语的，没人三种

都会。

问：多少人只会两种。只会两种=全部-会三种-只会一种-任何一种都不会

条件1.只会英语的60个。只会两种=200-0-70-60-0-任何一种都不会，不充分

条件2.任何一种都不会的20个。只会两种=200-0-70-0-20-只会英语，不充分

两条件一起考虑，只会英语的60个，任何一种都不会的20个。只会两种=200-0-70-60-0

-20=50，充分

KEY：C