Q1:What is the probability that event E or event F or both w

Q1:
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
Q2:
Last year in a group of 30 businesses,21 reported a net profit and 15 had investments in foreign markets.How many of the businesses did not report a net profit nor invest in foreign markets last year?
(1) Last year 12 of the 30 businesses reported a net profit and had investments in foreign markets.
(2) Last year 24 of the 30 businesses reported a net profit or invested in foreign markets,or both.
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.
第一题答案为E,第二题答案为D.
第一题为什么不选C 我觉得应该是0.4+0.6+0.4*0.6
yykkhl 1年前 已收到1个回答 举报

zzmingzz 幼苗

共回答了18个问题采纳率:83.3% 举报

Q1:概率 - 互斥事件与独立事件
  the probability that event E or event F or both will occur实质上就是问P(E∪F)的值
Statement (1):Insufficient
  Statement (2):Insufficient
  Together:由于题目中并未给出事件E和事件F的关系,(1)+(2)分两种情况:
  ①如果E和F为互斥事件,P1=P(E)+P(F)=0.6+0.4=1
  ②如果E和F为独立事件,P2=P(E)+P(F)-P(E∩F)=0.6+0.4-0.6*0.4=0.76
  P1≠P2,Insufficient
  选E


Q2:集合 - 韦恩图
  设both report a net profit and invest in foreign markets的Business数量为X,not report a net profit nor invest in foreign markets last year的Business数量为Y,如图所示.


  条件一:Business总数为30

  条件二:Report a net profit 的Business为21

  条件三:Invest in foreign markets 的Business为15
  根据以上条件可以列出等式:Y=30-(21+15-X) => Y=X-6
Statement (1) :

  => X=12=>Y=6,Sufficient
Statement (2) :

  => 21+15-X=24 => X=12 => Y=6,Sufficient
  选D

1年前

1
可能相似的问题
Copyright © 2024 YULUCN.COM - 雨露学习互助 - 16 q. 0.027 s. - webmaster@yulucn.com