每天Prep一问，数学心里有底，NN指点

norlanzhang

1.If x>y^2>z^4, which of the following statements could be true?
i. x>y>z
ii. z>y>x
iii. x>z>y
A.i only
B. i and ii only
C. i and iii only
D. ii and iii only
E. i,ii,and iii
最后选的E，I wonder ii为什么也可以啊？

2. Acommitee of three people is to be chosen from four married couples. What is the number of different committees that can be chosen if teo peiple who are maried to each other cannot both serve on the committee?
A. 16 B. 24 C. 26 D. 30 E.32
像这样的概率我真是弱爆了，求思路步骤啊~~

wuyulunbi

第一题：1、x=100.y=5.z=1   2、x=0.4.y=0.5.z=0.6   3、x=100.y=-5.z=1 所以选E

第二题：题干最后有问题吧if the people who are maried to each other cannot both serve on the committee?
             从4对夫妇中选三个人组commitee，三个人互相不是夫妻
       C43，从4对中选出3对
       2*2*2，没对有男人和女人两种情况
       so，4*2*2*2=32，选E

norlanzhang

第一题：1、x=100.y=5.z=1   2、x=0.4.y=0.5.z=0.6   3、x=100.y=-5.z=1 所以选E

第二题：题干最后有问题吧if the people who are maried to each other cannot both serve on the committee?
             从4对夫妇中选三个人组commitee，三个人互相不是夫妻
       C43，从4对中选出3对
       2*2*2，没对有男人和女人两种情况
       so，4*2*2*2=32，选E

-- by 会员 wuyulunbi (2012/3/5 21:36:36)

呃...我打错了。顿悟，多谢啦！