讨论几道机经

以下都是八月份总结好了的机井，但是有几题不明白， 下星期二就考了， 希望大家帮帮忙

21.Define f(x)= the product of consecutive positive integers,

e.g. f(12)=2*4*6*8*10*12,  what is the largest prime factor of f(24)

22.A table of energy (water?) consumption of at least 9 countries,

average in amount per person. 罗马数字题。

I. Japan is 10 times of Haiti’s consumption per person.

II. 我不太记得了, 但是是正确的  

III.The average of consumption in China and Haiti combined is …(a fixed number) 只记得此处不知两国人

44.DS：N=P+Q+R，P，Q，R是连续整数，N=XYZ，X，Y，Z是连续整数，

问N被5除余几

a) P被5除余1

b) X被5除余1

参考答案：D

49.题干很长,There are three kinds of bonus, each is $750,$1500,$5768, the company will give bonus to

its employees. Each bonus has be to signed to at least one person,  Now the company has the total

bonus of 5xxxx. What is the minimum number of employees who can get the bonus?

A.10  B. 11 C.12. D 13  E. 14  应该是10 对吧？

还有一个数学的理解问题， 是说Tenth digit , 这样的单词， 是不是指小数点的十分位啊？

关于那种最大公约数的题目，我没有什么把握， 不知道这种题目的一般思路是怎样的

一次就问了这么多问题，谢谢大家了。我做GWD的数学觉得时间很紧，不知道真正考试的时候会不会好一点。而且我觉得GWD的数学部分， 有一定的难度， 我都错3-4 个。现在还有几套我不想做了。我想6，7，8三个月的机井应该差不多了吧

if f(12) = 2*4*6*8*10*12, then f(24) = 2*4*6*8*10*12*14*16*18*20*22*24, the largest prime factor is 11, where 22 = 2 * 11

N=P+Q+R，P，Q，R是连续整数，N=XYZ，X，Y，Z是连续整数，

1) P被5除余1

so p = 5m + 1, and since p, q, r are consecutive integers, q = 5m + 2, and r = 5m + 3, thus, n = p + q + r = 15m + 6 = 15m + 5 + 1 thus the remainder of (15m + 5 + 1) / 5is 1, so 1) is sufficient

2) X被5除余1

so x = 5n + 1, and since x, y, z are consecutive integers, y = 5n + 2, and z = 5n + 3, thus, n = x * y * z = (25n^2 + 15n + 2)(5n + 3) = 125n^3 + 150n^2 + 6, thus, the remainder of that junk you saw divide by 5 is 1, thus 1) is sufficient

therefore, the answer is D

22.A table of energy (water?) consumption of at least 9 countries,

average in amount per person. 罗马数字题。

I. Japan is 10 times of Haiti’s consumption per person.

II. 我不太记得了, 但是是正确的  

题目不全吧...

还有一个数学的理解问题， 是说Tenth digit , 这样的单词， 是不是指小数点的十分位啊？

so .56874, the tenth digit is 5; .0239472398 the tenth digit is 0

49 题我记得有讨论过, 好象是说12, 'cause to ensure the number 5xxxx is not like 59999, so 12 covers over 60000, something like that, im not sure though, there could be real numbers involved...

"我做GWD的数学觉得时间很紧，不知道真正考试的时候会不会好一点。而且我觉得GWD的数学部分， 有一定的难度， 我都错3-4 个。现在还有几套我不想做了。我想6，7，8三个月的机井应该差不多了吧"

I don't know if gwd help that much, focus on jj, but focus more on the ways to think of the problems rather than just the answers, 'cause you never know when ETS will switch up on ya

那么就考好一点, 不枉我们的努力了, 呵呵...