扫描二维码，直接登录
题库 / Prep2007E1-DS-158
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) The probability that the ball will both be white and have an even number painted on it is 0.
(2) The probability that the ball will be white minus the probability that the ball will have an even number painted on it is 0.2.
Statement (1) ALONE is sufficient, but statement (2) alone is not sufficient.
Statement (2) ALONE is sufficient, but statement (1) alone is not sufficient.
BOTH statements TOGETHER are sufficient, but NEITHER statement ALONE is sufficient.
EACH statement ALONE is sufficient.
Statements (1) and (2) TOGETHER are NOT sufficient.
P（白球∪偶数）= P（白球）+ P（偶数）- P（偶数白球）
条件一：P（偶数白球）= 0，不充分，白球都不是偶数不代表偶数都不是白球；
条件二：P（白球）- P（偶数）= 0.2，不充分
结合还是无法求得
登录 或 注册 后可以参加讨论