[求助]GWD-18-32

bioliwu

Q32:

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.

A. Statement (1) ALONE is sufficient, but statement (2) alone is not sufficient.

B. Statement (2) ALONE is sufficient, but statement (1) alone is not sufficient.

C. BOTH statements TOGETHER are sufficient, but NEITHER statement ALONE is sufficient.

D. EACH statement ALONE is sufficient.

E. Statements (1) and (2) TOGETHER are NOT sufficient.

Answer: C*E

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?

0.22

A. 0.32

B. 0.37

C. 0.46

D. 0.63

Answer: d*B

请教思路,谢谢

bioliwu

Q22:

If –2x > 3y, is x negative?

(1) y > 0

(2) 2x + 5y – 20 = 0

A. Statement (1) ALONE is sufficient, but statement (2) alone is not sufficient.

B. Statement (2) ALONE is sufficient, but statement (1) alone is not sufficient.

C. BOTH statements TOGETHER are sufficient, but NEITHER statement ALONE is sufficient.

D. EACH statement ALONE is sufficient.

E. Statements (1) and (2) TOGETHER are NOT sufficient.

Answer: A*D

请教思路,谢谢

oldersea

试着解答，lz给的答案是不是说后面的是正确地，前面的是自己做的？我想了半天，汗

Q32,因为没说E和F的关系，所以没法求出E，F一起发生时的概率。

QX，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，以A肯定是不对的。

Q22，条件1是没问题的，充分，条件2的等式可以求出y=x的一个表达式，带入已知条件-2x>3y，可以求出x也是小于0的，所以选D。