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标题: prep DS CR請教 [打印本页]

作者: landy6320 时间: 2008-8-2 09:26
标题: prep DS CR請教

不好意思我第一次po文問問題如有不對之處敬請見諒!

prep DS1-169

169. 16735-!-item-!-187;#058&010875

If the integers a and n are greater than 1 and the product of the first 8 positive integers is a multiple of aⁿ, what is the value of a ?

(1) aⁿ = 64

(2) n = 6

如何得知(2)的2^6會等於64 從(2)中你怎麼會知道a等於2呢?prep DS2-60

60.
4972-!-item-!-187;#058&004074

Does the integer k have a factor p such that 1 < p < k ?

(1) k > 4!

(2) 13! + 2
k 13! + 13

不懂(2)為什麼可以得知

CR PREP-2 42

42.
(32943-!-item-!-188;#058&007554)

Researchers have found that when very overweight people, who tend to have relatively low metabolic rates, lose weight primarily through dieting, their metabolisms generally remain unchanged. They will thus burn significantly fewer calories at the new weight than do people whose weight is normally at that level. Such newly thin persons will, therefore, ultimately regain weight until their body size again matches their metabolic rate.

The conclusion of the argument above depends on which of the following assumptions?

(A) Relatively few very overweight people who have dieted down to a new weight tend to continue to consume substantially fewer calories than do people whose normal weight is at that level.

(B) The metabolisms of people who are usually not overweight are much more able to vary than the metabolisms of people who have been very overweight.

(C) The amount of calories that a person usually burns in a day is determined more by the amount that is consumed that day than by the current weight of the individual.

(D) Researchers have not yet determined whether the metabolic rates of formerly very overweight individuals can be accelerated by means of chemical agents.

(E) Because of the constancy of their metabolic rates, people who are at their usual weight normally have as much difficulty gaining weight as they do losing it.

覺得題目好繞喔看不太懂他的意思不知道他要問什麼

拜託哪位牛人出手解救我吧拜託拜託謝謝感激萬分!

作者: jh1904 时间: 2008-8-2 14:36
1. 8! = 2^7*3^2*5*7, a^n is a factor of 8!

(1) a^n = 64, (a,n) can be (2,6), (4,3), (8,2), insufficient

(2) n=6, then a = 2 because if a < > 2, then a^n would not be a factor of 8!

2. p is a factor of k other than 1, k can not be a prime number.

(1) k>4! , k can be any prime number > 24 that p doesn't exist

(2) 13!+2 < k < 13!+13, k can be 13!+3, 13!+4..... 13!+12, that has 3,4,5.....12 as its factor.

3. Is the answer C?

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