【输血】贰越易昊输血讨论稿1-100 【注意：这是二月，三月已换库】

xxakromaxx

jiayou !!!!!!!!!!!

success2013

41题条件1不充分，比如X是根号8

不落草

感谢！

baniubi

peachjudy13

success2013 发表于 2014-2-11 02:51
41题条件1不充分，比如X是根号8

题目已经说x是一个integer

peachjudy13

wq125583440 发表于 2014-2-10 23:55
不知道会不会沉了哎。55题应该选A哦，当x>0时，X+1/X>=2，是恒成立的。

可是题目问的是>y不是大于等于y。所以根据x是否等于1会有两种结果 一种是x+1/x = y；一种是x+1/x >y。条件不充分。

peachjudy13

automne7 发表于 2014-2-11 00:05
感觉69有问题。其中一艘船走了80，怎么可能一开始与另一艘船的距离是10，而且还是路线垂直？ ...

我们用东南西北来说吧 这样比较清楚。港口在中间，A船从南边开到港口，B船从东边开到港口。他们俩的路线是垂直的，条件一是这个意思。相距十米，是路程自称的直角三角形的斜边长。不过这个数值确实有点小，不过大概就是这么一个意思啦~也许不是十米是100呢~

tokoto

fighting!!!!!!!!!!!

baniubi

hi,  to those who are still confused with question # 12,  i have come up with another way to sovle it.   
for 3 letter codes, there are 6 different outcomes ----PPP,PPE,PPR,EEP,EER,PER.   there is only one way to arrage codes with outcome of ppp, and there are 6 different ways of last outcome of PER, caculated by  (3!). however, for the rest of three outcomes in the middle, we have duplications; therefore, we need to take it into account when arraging those outcomes. the way to do it is, for instance,from first glance, there are six possible way to arrage PPE, but P repeat twice, so,we need to take out those duplucations. ( 3!/2!), as a result, there is only 3 distinct outcome for PPE. we can do other two in the same way. the total number of way to form code is 1+3!+3*3!/2! =19. hope it helps...    my QQ is 247376397, if any one of you want to discuss more QM, please feel free to contact me..

quincywen

谢谢拉。