M51. Share Math JJ with CDer. Thank you all!

AA

“Our factory in Cookville is our most advanced and efficient. It is capable of producing ten drill bits for each dollar of production costs, whereas none of our other factories can produce more than seven drill bits per dollar of production costs. Therefore, we can reduce our overall drill bit production costs by devoting the Cookville factory entirely to drill bit production. Since reducing the production costs of individual machine parts is the only way to achieve our larger goal of reducing our overall production costs, dedicating the Cookville factory entirely to drill bit production and shifting all other machine part production to our other factories will help us to attain that larger goal.”

Key Points: “the only way”? “individual machine à overall cost”? “shifting machineàreduce cost”? “market can absorb the extra more drill bits”?

AI 找了，没找到，记得很清楚是：

“The quality of our life have been improved compared to our past because of the advancements of business and technology.”

Key points: both enhancements & drawbacks: internet provides more accessibility, convenient, save time etc…but also bring annoyance & irritation, such as bank phone calls

Math JJ 有陷阱，跟旧JJ偷换了数字的

28（PS）A{1,2,3,4,5} B{2,3,4,5,6} C{4,6,8,10,12,14} 问A交B交C是多少（取公共元素）

答案是{4} 

37（PS）x + 2y + 3z = 9 （我的这里是7），x + 3y + 5z = 12。
                    问x + y + z = ?

先用x + 3y + 5z = 12减去x + 2y + 3z = 9

得出y + 2z = 3

最后x + y + z = x + 2y + 3z - (y + 2z) = 9 – 3 = 6

答案是6；（我的答案是2）

有一题极为吐血，开始看不懂题，其实问的是下面哪个分数的小数位数是有限个？Which of the following fractions, the decimal has finite number of the digits after the decimal point? 吐血，花了3-4分钟。

答案是C. 大家看到就先算C的。具体数字我搞了半天还是记不起来。

1 person use 1000 dollar, and put in a semi-annual interest savings rate is r percent, ask for the interest of 1000 after one year.

开始把interest当r算，结果没答案。注意题目是r%!我开始算漏了那个百分号，结果重新算, 阴险！

1000*(1+r%/2)^2-1000=0.025r^2+10r

62（DS）有一个容器，在昨天下午1点的时候，有一些溶液在容器里。A每x小时注入y（x.y都是具体的数，不过我忘了）B每5小时注入溶液250000，C每3小时可以抽掉330 000，且当溶液到达2500000的时候停止注入。问在昨天下午1点的时候容器里有多少溶液呢？

1：昨天下午4点时容器是2500 000

2：昨天下午2点时容器有2100 000

答案是B

1 rectangular field. The length draw from one corner to the diagonal corner is 130. Ask how long is the length of the field

1) the perimeter of the field is know

2) the length of the field is shorter by two compared to the width.

D

83（DS）上个月题目3*3^a /8* 3^b是多少？(数字小变，分子多3，分母多8)

1：a + b = 4

2：a – b = 3

答案是B

91（PS）一个人三天到单位和离开单位的时间，求这三天在工作的总时间？

到达8：30  离开6：10

到达8：10  离开5：05

到达8：00  离开5：30

答案是28小时5分

93（DS）=130题

说一个有X个小正方体组成的长方体，如果用油漆涂他的表面，而油漆的价格是每单位Y cents（单位是乱编的），那么涂满长方体需要多少钱？（x，y均为数字）

1：告诉涂满所有小正方体表面的钱

2：x=2

A

wind blow towards a wall. The force can be expressed as F1=k*A1*V1^2, another wall is F2=k*A2*V2^2; A2=1/2A1; F1=2/3F2. ask v2 in terms of v1.

具体数字不是很清楚了，最后答案是: 根号3*v1.

100（PS）Set of numbers in lines. Line l has 5 numbers, another which 平行有4个点，问这些点最多组成多少个三角形？

一条线上5个点，另一条平行线4个点，在这些点上共可以组成多少个三角形？

a. 1

b. 3

c.10

d.70

e.210

cde忘了

C52*C41+C42*C51=70  

答案是70个

106（DS）Is the least temperature below zero?

1：median < 0 （可能都小于0，可能比一半多一点的数字小于0，确定）

2：average >0（可能大部分都小于0，但是突然有一个非常大的值把average拉

答案是A

117（DS）讲一个连续数组S_n从S₁到S_n. 问n的值是多少？

1：知道数组的平均值是40（知道总和）

2：The term after the first is 1 more than the former.（知道是等差数列）

1+2：不知道首项，还是不知道

选E

118 （PS）说一种东西含30%的sand 和70%的别的物质。要使变成含50%的sand和别的物质，需要多少量的原来东西换成sand，总量是10克

一种东西p=10gram含有30% sand和70%另一种物质（简写W）。现在多少P换成sand能使P含有50%sand和 50%W

答案
                    选项：2.9

119一个公司员工工资中数是35000，一共127人，问下面哪个对

1）at least 63 人大于或等于35000

2）at least 63 人小于35000

3）at most 63 人大于或等于35000    

选只有1对

133（DS）2 t u是一个三位数， t和u分别为1到9之间的数。问2 + t + u 是否能被9整除.

1：u=9（不行）

2：t + u能被3整除  (具体数字记不清楚了，根据 t u的乘积大于等于50可以选了E

165（PS）说顶楼有1个office(应该是office,不清楚)，每一层楼的office数都是它上面那一层的2倍，说总共有X层,the lowest floor有多少个office?

(用X表示)

答案应该是2^(x – 1)

New: X=1/28+1/31+1/42

1)      X< 3/28

2)      X=3/31

3)      X>3/42

Anwer: 1 & 3

条件2 费时间算，大家记着好了。

语文前10题不在状态，应该是掉到低分库勒。因为15题后面的都比较简单，而且阅读我的只有3篇：书店，签协议书，一个关于女性地位影响（主体题）。阅读感觉题目跟JJ的有不一样的，应该是低分库德原因。阅读JJ的都是牛人。

总体感觉，应该是最后做得比前面好，所以难度慢慢上才有670，M51, V28。最后出来下面这个SC。以前做过，直接选了。看到SC，CR在后面才上难度，估计后面才做对多一点。所以大家不要看到简单，低分库勒就放弃，后面做好，我觉得上700还是有希望的。我最后时间不够，最后3题乱点的。

SC: 一道GWD

（1）    GWD-28-Q30

Unlike the body’s inflammatory response to cuts and sprains, with widespread swelling and stiffness immobilizing the injured area until it heals, the body’s response to sunburn is more localized and resulting in a distinct line dividing affected and unaffected areas of the skin.

A: with widespread swelling and stiffness immobilizing the injured area until it heals[CH1] , the body’s response to sunburn is more localized and resulting[CH2] 

B: where the injured area is immobilized with widespread swelling and stiffness until it has healed, sunburn[CH3]  generates a more localized response in the body, which results instead

C: with the injured area immobilized by means of widespread swelling and stiffness until healing, sunburn[CH4]  generates a more localized response in the body, one resulting

D: in which widespread swelling and stiffness immobilize the injured area until it has healed, the body’s more localized response to sunburn results

E: in which widespread swelling and stiffness immobilize the injured area until healing[CH5] , instead, the body’s more localized response to sunburn results

133（DS）2 t u是一个三位数， t和u分别为1到9之间的数。问2 + t + u 是否能被9整除.

1：u=9（不行）

1 rectangular field. The length draw from one corner to the diagonal corner is 130. Ask how long is the length of the field

1) the perimeter of the field is know

2) the length of the field is shorter by two compared to the width.

1 rectangular field. The length draw from one corner to the diagonal corner is 130. Ask how long is the length of the field

1) the perimeter of the field is know

2) the length of the field is shorter by two compared to the width.

133（DS）2 t u是一个三位数， t和u分别为1到9之间的数。问2 + t + u 是否能被9整除.

1：u=9（不行）