Re: [計量] 請教一題印度機經

看板GRE作者b94501010 (海鮮不新鮮)時間16年前 (2008/07/22 00:30)推噓2(2推 0噓 1→)

留言3則, 2人參與討論串2/2 (看更多)

※ 引述《kakugirl (kaku)》之銘言： : Given total number of students as 120 & : Number of students learning Spanish = 40 : Number of students learning French = 60 : Number of students learning Russian = 80 : Number of students learning 2 languages = 50 : Number of students learning all 3 languages = 10 : Find number of students learning none of these languages? : 請問一下大家這題要怎麼解呢? : 我對這種題目超沒概念 : 非常謝謝!! Let (x+10) denote number of students learning both Spanish and French (y+10) denote number of students learning both Spanish and Russian (50-x-y+10) denote number of students learning both French and Russian => number of students learning only Spanish = 40-(x+y+10) = S number of students learning only French = 60-(x+10+50-x-y) = F number of students learning only Russian = 80-(y+10+50-x-y) = R By adding S, F, R, and 60 together, we can know the number of students learning at least one of these languages, which is denoted by M. Then we subtract M from 120 to get the number of students learning none of these languages. -- ※ 發信站: 批踢踢實業坊(ptt.cc) ◆ From: 61.217.109.187 ※ 編輯: b94501010 來自: 61.217.109.187 (07/22 00:35)

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beban

07/22 15:00, , 1^F

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syman

07/24 02:06, , 3^F

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