GRE课程
相较于Verbal，GRE的Quantitative部分是绝大多数同学的得分利器，大家的目标也基本都锁定在168+，甚至于满分。
虽然GRE数学的考点对中国学生来说，相对容易，但想要考一个高分甚至满分，也并不如想象中的那么简单。尤其近年来，难题、坑题、长题出现的频率逐渐变高，考生在考场上一不小心就会失分。
就连GRE Verbal能拿到169的Chatgpt-4，面对GRE数学，也只能拿到163。而根据2021-2022年GRE官方报告，中国学生的平均GRE分数已经达到165.9了！
要想不在数学上被拖后腿，细节一定要注意！今天就带大家梳理一下GRE数学常见的六大失分点！避开这些雷区，向着满分冲刺💯！
很多同学常常考试的时候觉得题目自己都会，但总是做做错，很可能就是因为没有仔细读题。
比如下面这道题，问的是在science club的学生中不在band里面的百分比，所以得用15%/20%=75%，而不是直接等于15%.
例题
Of the students in a school, 20 percent are in the science club and 30 percent are in the band. If 25 percent of the students in the school are in the band but are not in the science club, what percent of the students who are in the science club are not in the band?
A. 5% B. 20% C. 25% D. 60% E. 75%
刚刚开始备考GRE数学的同学往往会在几何题上踩雷：主观做出题目没给出的假设。
例题
∠C=89°.
Quantity A: Length of AB
Quantity B: Length of BC
A. Quantity A is greater.
B. Quantity B is greater.
C. The two quantities are equal.
D. The relationship cannot be determined from the information given.
例如这道题，答案就是D，因为在GRE数学考试中并不保证图形会按照相应的比例绘制：there’s no guarantee that a figure will be drawn to scale on the GRE。
做任何题都要随时记得把0和1带进去试试，看看是否符合要求。
例题
If x is an odd negative integer and y is an even integer, which of the following statements must be true?
I. (3x - 2y) is odd
II. xy2 is an even negative integer
III. (y2-x) is an odd negative integer
A. I only
B. II only
C. I and II
D. I and III
E. II and III
这道题的答案是A，大家容易错选C。要考虑到如果y是0的情况,在这种情况下，xy^2就不是negative integer。
在计算题中忽略最小质数也是非常常见的失分点。
例题
n is an even integer.
Quantity A: The number of prime factors of n
Quantity B: The number of prime factors of n/2
A. Quantity A is greater.
B. Quantity B is greater.
C. The two quantities are equal.
D. The relationship cannot be determined from the information given.
答案: D. 最小的质数是2,也是唯一的偶数。当n=2 的时候, Quantity A 是一个prime factor, Quantity B是0个prime factor当n=4的时候, Quantity A和Quantity B相等
“must be” and “could be”在GRE数学中，一定要注意区分。
Must be = Always correct
Could be = answer only holds true in certain instances
例题
c and d are prime numbers. If c – d is an odd integer, then which of the following must be true?
A) c is even
B) d is odd
C) c*d is odd
D) d is even
E) c*d +1 is odd
因为c和d都是prime且要满足c-d是odd, 说明c和d一个是odd, 一个是even。在所有prime中只有2是even, 所以c和d中一定有一个是2. 选项中 A,B,D都是could be true, C选项 c*d 一定是even. 所以答案选E。
符号单位也是做题的时候要特别注意的，一旦忽视这道题必错无疑。
例题
Quantity A: 0.05 percent of 4000
Quantity B: 1/200 of 4000
A. Quantity A is greater.
B. Quantity B is greater.
C. The two quantities are equal.
D. The relationship cannot be determined from the information given.
这道题在计算的时候要注意，percent 需要除以100, 所以0.05 percent of 4000= 0.05*4000/100 = 2, 所以答案选B。
遇到以上六种情况，即使是数学基础非常好、已经掌握考点的同学都很有可能踩雷。在日常做题的时候，同学们一定要保持警惕、多多思考关注细节，避免因为这些小失误而痛失高分！
