[求助]gwd 18-32

What is the probability that event E or event F or both will occur?

(1)   The probability that event E will occur is 0.6.

(2)   The probability that event F will occur is 0.4.

答案为什么是E？我选C

a typical eithor-or choice.

they can be either mutually exclusive or intersected

请教NN一下，32的QX怎么做啊？

QX:

If the probability is 0.54 that Stock A will increase in value during the next month and the probability is 0.68 that Stock B will increase in value during the next month, what is the greatest possible value for the probability that neither of these two events will occur?

A.        0.22

B.     0.32

C.      0.37

D.     0.46

E.     0.63

這題我怎麼算都是 0.1472 啊!

因為A不增值的機率是0.46，B不增值的機率是0.32，同時不增值的機率為0.46*0.32。

思路這樣對否??請指點

我和楼上的也一样，这样算出来是0.1472。

NN说应该这样算：stock A不增加的概率是0.46，stock B不增加的概率是0,32，所以两个股票都不增加的概率最大可能是0.32，以小的概率B为准。

我不明白，有人解释一下吗？为什么以小的概率B为准？