一道GMAT数学DS题
问题描述：
一道GMAT数学DS题
Each of the 25 balls in a certain box is either red, blue or white and has a number from 1 to 10 painted on it. If one ball is to be selected at random from the box, what is the probability that the ball selected will either be white or have an even number painted on it?
1)\x09The probability that the ball will both be white and have an even number painted on it is 0.
2)\x09The probability that the ball will be white minus the probability that the ball will have an even number painted on it is 0.2.
求知问题翻译跟答案解析.
答
楼下没答案啊这道题选E,这道题题目是问你P(A+B) = P(A) + P(B) - P(AB)1P(AB)=0是不充分的.因为如果同时发生的概率为0那么说明白球上都不是偶数,但是不代表不是偶数的都是白球.所以不充分所以锁定选项B/C/E2白球的概...