Q9: If an integer n is to be chosen at random from the integers 1 to 96, inclusive, what is the probability that n(n + 1)(n + 2) will be divisible by 8?
A. 1/4 B. 3/8 C. 1/2 D. 5/8 E. 3/4
答案是D。虽然做对了,但是用的方法不是很简便,请高人帮我指点迷津!
Q16: What is the probability that a student randomly selected from a class of 60 students will be a male who has brown hair? (1) One-half of the students have brown hair. (2) One-third of the students are males. 这道题目我做的也是对的,答案是E。但是不知道我的思路有没有问题。我是这么想的:BROWN HAIR的是30个人,MALE是20个人。20个人有可能是完全独立于BROWN HAIR的30个人之外的,也就是也有可能BROWN hair的都是女生。 Q29: The annual rent collected by a corporation from a certain building was x percent more in 1998 than in 1997 and y percent less in 1999 than in 1998. Was the annual rent collected by the corporation from the building more in 1999 than in 1997? (1) x > y (2) xy/100< x – y
像这样子抽象的题目我就搞不清楚了。。。
暂时求教这么多。发现自己做数学的时候还是太大意了。很多题目没看清楚题干就解题了。哎,马上就要上战场了,应该要调整好心态。为自己,为战友们加油! |