对题意不太明白

mariezhu

How many people are directors of both company K and company R?
1. There were 17 directors present at a joint meeting of the directors of Company K and company R, and no directors were absent.
2. Company K has 12 directors and Company R has 8 directors.

The given answer is C.

How to understand? Thanks.

msryiyg2

有多少人既是k公司又是r公司的director?

1. 有17个director出席了k公司和r公司的会议

题目说两个公司一共有17个director, so A,D可排除

2. k公司有12个director, r公司有8个director

题目说两个公司的director分别是多少, 但没有说在K工作又在R工作的director有多少个, so B可排除

通过条件1和2, 我们用集合相交公式可求出问题, so E 排除, 答案是C

mariezhu

明白了,多谢