If 500 is the multiple of 100 that is closest to x and 400 is the multiple of 100 that is closest to y, which multiple of 100 is closest to x+y?
(1) x< 500
(2) y< 400
另外一题；（能否给个具体的解，求出人数）
of the 200 members of a certain association, each member who speaks German also speaks English, and 70 of the numbers 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.作者: amanda621 时间: 2010-7-25 13:12
第二题 我觉得是C 是50人 是这样的 一共200个人 lz可以画个图 一个方框代表一共是200个人 然后一个大圈代表说英语的 因为题目给出说德语的都说英语 因此德语的人应该包括在英语的范围里面 所以大圈里面有个小圈代表说德语的 另外在画一个圈是说西班牙语的 这时候有两种情况 第一和说英语的没有交集 第二有交集 但是因为没人会说三种 所以和英语有交集的圈不能再和德语有交集 根据1 表明 德语外英语里是60人 只知道只说西语的70 但不知道什么都不说的是多少人 所以不对 单独第二个条件更不充分 但是两个和在一起后 无论西语与英语是否相交 剩下的200-20-60-70=50 就是说两种语言的人作者: AppleStrudel 时间: 2010-7-25 13:31
1)E , 500 is the multiple of 100 that is closest to x 是最接近x的整百数 451<x<549, 351<y<449 当 x=451, y=351, multiple of 100 is closest to x+y = 800 当 x=499, y=399, multiple of 100 is closest to x+y = 900 结果不确定