→ koala0416:感謝感謝 09/16 12:03
※ 引述《koala0416 (koala)》之銘言：
: Q22:
: At the beginning of the year, the Finance Committee and the Planning
: Committee of a certain company each had n members, and no one was a member of
: both committees. At the end of the year, 5 members left the Finance
: Committee and 3 members left the Planning Committee. How many members did
: the Finance Committee have at the beginning of the year?
: (1) The ratio of the total number of members who left at the end of the year
: to the total number of members at the beginning of the year was 1:6.
: (2) At the end of the year, 21 members remained on the Planning Committee.
: 我自己認為是C 但答案給的是D 煩請高手解惑 感謝!
這題的重點在於no one was a member of both committees.
這讓我們鬆一口氣，不是那種包納式的集合(文氏圖)
FC 有n個人 PC也有n人
年底，FC = n-5 PC = n-3
問FC= n =??
條件一： (5+3) : (n+n) = 1:6
8 : 2n = 1:6
2n = 48 n = 24 SUFFICIENT
條件二： 年底PC = n-3 = 21 n = 24 SUFFICIENT
BOTH INDEPENDENTLY SUFFICIENT (D)
Dustin
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◆ From: 118.166.233.171
※ 編輯: danyuchn 來自: 118.166.233.171 (09/16 11:42)