: 1.If the slope of line l is 3, and point (k,5) is on the line.
: Quantity A: K
: Quantity B: 2
D
点斜式，点爱在哪就在哪，斜率爱多大就多大
: 2.What is the greatest prime factor of 3^100-3^97?
(3^3 -1)3^97 = 26*3^97 = 2*13*(3^97)
答案：13
: 3.Companies C1 and C2 are among 18 companies, if 4 companies are selected from
: all these 18 companies, how many selections of 4 companies including both C1
: and C2? (数字填空题)
C16取2=120 (就从另外16家公司选两家出来陪C1跟C2)
: 4.The lengths of two sides of a triangle are 5 and 12, which of following
: numbers could be the length of the other side?(不定项选择题)
: A. 3 B. 9 C. 10 D. 12
比(12+5)小 比(12-5)大 都可以
所以选 BCD
: 5.If p=r^n，r is a prime number，and n is a positive integer，then define
: p▲=rn，for example，25=5^2， then 25▲=5*2=10. what is value of 32▲?
32=2^5
答案2*5=10
: 6.A物品售出后盈利25%，B物品售出后亏了25%，最终售价都是2100，求A、B两种种物品起
: 始价格的和比4000多多少?
买进价格分别为a跟b
1.25a=2100, a=2100*0.8
0.75b=2100, b=2100*(4/3)
a+b=2100*(0.8+1.333) > 4000
注意：看清楚营利跟亏钱的"基数"是不是买进价格(成本)
: 7.If the standard deviation of a, b, c, d is 1, what is the standard deviation
: of a+1, b+1, c+1, d+1?
资料全体一同平移==>标准差不改变
: 8.一个班级共计25人，其中A所得到的分数比班级的平均分average多6.2，经过加试后，A
: 又多获得10分，其他同学成绩不变，求A的新成绩比班级的新的平均分多多少?
10/25 = 0.4
此人又多拿10分，拉高了全班平均0.4分
所以把个人成绩与班平均之间的差距又加大了10-0.4=9.6
所以此人的新成绩减去新的班平均为6.2+9.6=15.8
: 9.在一个圆内有个P点，圆的周长circumference是12。
: Quantity A: P点距离圆周最长的距离和最短距离的和
: Quantity B: 4
P点距离圆周最长距离 + P点距离圆周最短距离 = 直径
周长12，所以直径=12除以拍==>比4小
答案B
: 10.What is the ratio of furniture to items in all shaded area?(其他部分也有具体
: 的百分数)
没图不解
: 11.If f(x)=x^2+2x, g(x)=x-2, what is the least value of x when f(x)=g(x)?
: (数字填空题)
f(x) = g(x) 求解
x^2 + 2x = x-2 ==> x^2 + x + 2 = 0 ==> 无实数解
数字又背错了吗？
: 12.What is value of r percent of s percent of 200?
: A. rs/100 B. rs/50 C. rs/20 D. rs E. 50rs
看到percent就写个分母100，of就是乘，what 就是问号，BE动词就是=
? = (r/100)*(s/100)*200
==>答案B
: 13.In a certain sequence, the first term is x, and each term is -2 times than
: the preceding term, what is the sum of the first five terms?
是漏字还是多字呢？
-2 times than 这个用法怪怪的耶
3 times more than <