一眼看穿数学难题所在 教你发现GMAT真题中的隐藏条件
- 2016年01月04日16:37 来源:小站整理作者:orangejojo
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GMAT数学题对于中国考生来说也许是整个GMAT考试中最为友善,也最容易拿到高分的部分了。当然,这里的简单仅仅是指其中涉及的知识点。事实上许多中国考生都没能在GMAT实战的数学部分拿到足够理想的成绩。无法理解数学题目中的各种隐藏条件和语言陷阱就是罪魁祸首。下面小编就为大家详细介绍一些GMAT数学题中的隐藏条件。
GMAT数学难在哪里?
如开头所说,GMAT数学涉及的知识点,对于中国考生来说其实并没有多高的难度,大多是一些高中甚至初中阶段就已经接触过的内容,其中大部分还通过大量做题得到了充分的练习,虽然有些考生因为较长时间不接触而出现生疏,但总体来说比起要从头学起的美国考生还是好了不少的。真正让GMAT数学变得困难的是出题方式,或者说是题目的展现方式。一般来说,给数学题增加难度最常用的手法就是把一些简单的概念用复杂的方式来进行描述,把一些明显的数学信息通过语言转换隐藏到题目中。举个最简单的例子,N是个奇数。用GMAT的出题思路,可能就会被改成N除以2余数为1。通过这种拐弯抹角的方式,GMAT数学的难度在无形中就得到了提升。
如何看破GMAT数学中的隐藏条件和语言小花招?
那么,考生需要如何看破GMAT数学题目中的各种隐藏条件和语言小花招呢?最简单的做法,就是通过切身体会来记住。虽然GMAT数学题目的难度可能会通过变换语言方式得到提升,但能够变化的模式,其实也还是比较有限的。只要考生体验过一次,对其有所了解,想要再次难住考生就不太容易了。下面小编就给大家举一些例子。
隐藏信息实例讲解
1. the remainder when x is divided by 10 is 3.
2. p = n^3 – n, where n is an integer
3. integer y has an odd number of distinct factors
4. |b| = –b
5. the positive integer q does not have a factor r such that 1
6. n = 2k + 1, where k is a positive integer
7. a^2b^3c^4 > 0
8. x and y are integers, and y^x < 0
9. what is the greatest integer n for which 2^n is a factor of 96?
隐藏条件实例分析
上面这些题目,其实本身都隐藏了许多额外的信息,下面就为大家逐条分析。
1. The units digit of x is 3 (the remainder when divided by 10 is always the same as the units digit).
2. p is the product of 3 consecutive integers. Factor out n first: n(n^2 – 1). Then, factor the difference of squares: n(n + 1)(n – 1). A number × one greater × one smaller = the product of 3 consecutives.
3. y is a perfect square (like 9, whose factors are 1, 3, & 9). Any non-square integer will have an even number of distinct factors (e.g. 5: 1 & 5, or 18: 1, 2, 3, 6, 9, & 18).
4. b must be negative. If the absolute value of b is equal to -1 times b, then b cannot be positive or 0; it must be negative.
5. q must be prime. If q were a non-prime integer, it would have at least one factor between 1 and itself.
6. n is odd. 2k must be even (regardless of what k is), so adding 1 to an even will give us an odd.
7. b must be positive. The even exponents hide the sign of a and c, but a^2 and c^4 must be positive, so b^3 – and therefore b – must be positive.
y must be negative, because only a negative base would yield a negative term. Andx must be odd, because an even exponent would make the term positive.
How many factors of 2 are there in 96? If we break 96 down, we get a prime factorization of 2×2×2×2×2×3, so 2^5 will be a factor of 96, but 2^6 won’t.
通过上述介绍和实例讲解分析,相信大家对于如何看破和发现GMAT数学题目中的隐藏条件和信息,都会有更为明确的认识和见解。希望上文内容能够帮助大家更全面地了解GMAT数学并做好备考工作,祝大家都能在GMAT考试中取得优异成绩。