GRE/GMAT数学考试中常见的10个错误陷阱【转载】
1. 词汇问题
(1) real numbers/ integers
一定注意题干的说明,到底是实数还是整数
(2) leg/ mode/ units digit
leg特指直角三角形的直角边,hypotenuse 代表直角三角形的斜边
mode是统计学中的众数,且可能不ONLY
units digit=ones digit 个位数的意思
2. 短语问题
(1) more than/ greater than 多于/大于
(2) greater than or equal 大于或等于
(3) there are twice as many a as b 指的是 a=2b
(4) x percent of y=y percent of x(错误率极高)x% * y= y% * x
1. factors 包含负值,比如4的 factors 包括1, 2, 4, -1, -2, -4,共计6个(考试一般只考正的)
2. 余数的运算过程可以有负整数的参与,如-17/ 7=-3…4(不过不怎么考)
3. 题干中可能只说 a, b, c,并没有说是 positive numbers a, b, c
1. 圆周率pi需要估值的话先按照3.14来算,不要按照3来算
2. -36.5 rounded to the nearest integer is -37
3. 0.16 rounded to the nearest 0.05 is 0.15
(0.81 rounded to the nearest 0.05 is 0.80)
1. 分母不能为0
2. 偶次根号下面的数值必须非负
1. (5)(6)(7)(8)(9)= 5*6*7*8*9=15120
2. m平行n,官方会写成:m || n,国内中学阶段一般会斜着写
1. 25 percent of the students taking math also take English.
1. 排列组合当中数位问题的顺序要求,是all digits cannot be repetition 还是neighbor digits cannot be repetition.
2. 25! 不是25感叹号,而是25的阶乘(factorial)(有木有很搞笑,但确实不少同学看错……)
1. 指数运算竟然自己创造公式……(竟然还大有人在……)
2. 乘法口诀竟然背窜……(比上一个错误人还多……)
1. 大小比较题,用带数法做题的时候,避免带入一个数值就直接下结论(限GRE)
2. ds题中,考虑条件充分性时,一定要依次考虑,考虑条件二的时候不要把第一个条件也放进来(限GMAT ds题)
1. Geometric figures are not necessarily drawn to scale(限GRE)
2. A figure accompanying a problem solving question is intended to provide information useful in solving the problem. Fitures are drawn as accurately as possible. Exceptions will be clearly noted.(限GMAT ps题)
3. Figures conform to the information given in the question, but will not necessarily conform to the additional information given in statements (1) and(2). (限GMAT ds题)