帮帮吧 数学

wintertrain

图表如下：
    Favorable    Unfavorable    Not Sure
Candidate M    40    20    40
Candidate N    30    35    35
题目 ：
The table above shows the results of a survey of 100 voters who each responded “Favorable” or “unfavorable”or “not sure” when asked about their impressions of Candidate M and of Candidate N.
What was the number of voters who responded “favorable” forboth candidates?     如果数据没变，应该是10人
(1)The number of voters who did not respond “favorable” for either candidate was 40
(2)The number of voters who responded “unfavorable” for both candidates was 10

wintertrain

谢谢@

mba2013

选A 单看第一栏 favorable 会比较清楚
楼上的说的听清楚~~

liulu007

这题就是选A的。有条件一可得出 respond “favorable” for either candidate or candidate was 60, then on the favorable condition M(40)+N(30)-M&N(60)=MN=10.
而，单独由条件二无法得出结果~

WALLMAGE

A......?