详情

　　在做题目的时候总会做到一些需要用数学公式计算的题目，很多同学就感到有些困扰，我什么时候需要用到这些内容，遇到的时候该怎么去用?今天我们就来捋一捋那些GMAT逻辑题中的数学考点。接下来跟小编一起来看看吧。
　　在所有的逻辑题中，常考到以下集中逻辑考点：
　　① 大小关系
　　② 公式关系
　　③ 表格对比
　　④ 百分比= 分子/分母;韦氏图;percentage≠ number：
　　⑤ 总量= 均量 ?数量：
　　⑥ 平均值/总rate=总量/数量=加权平均：
　　我们今天就中两种来站看讲解一下，大家先看做一下下面的题目
　　 例1 That the application of new technology can increase the productivity of existing coal mines is demonstrated by the case of Tribnia's coal industry. Coal output perminer in Tribnia is double what it was five years ago, even though no new mines have opened.
　　Which of the following can be properly concluded from the statement about coal output per miner in the passage?
　　(A) If the number of miners working inTribnian coal mines has remained constant in the past five years, Tribnia's total coal production has doubled in that period of time.
　　(B) Any individual Tribnian coal mine that achieved an increase in overall output in the past five years has also experienced an increase in output per miner.
　　(C) If any new coal mines had opened in Tribnia in the past five years, then the increase in output per miner would have been even greater than it actually was.
　　(D) If any individual Tribnian coal mine has not increased its output per miner in the past five years, then that mine's overall output has declined or remained constant.
　　(E) In Tribnia the cost of producing agiven quantity of coal has declined over the past five years.
　　答案: A
　　解析：
　　首先根据问题的要求可以判断这是一道归纳推理题。归纳题的做题要求是把文章中的事实进行总结或者合理推测，选出五个选项中可以合理推测的内容。
　　Fact 1：T的煤炭产业可以证明技术增加生产力
　　Fact 2：尽管没有新矿开，但是T的人均煤炭产出翻番了。(per miner是一个可能出现考点的标志词，而这里会考到的考点是：总量=均量??数量)
　　(A)If the number of miners working in Tribniancoal mines has remained constant in the pastfive years, Tribnia's total coal productionhas doubled in that period of time. 2Total=2output/miner?number，总量均量数量基本公式。如果数量不变，而文章说均量double，那么总量double，正确答案。
　　(B) Any individual Tribnian coal minethat achieved an increase in overall output in the past five years has alsoexperienced an increase in output per miner. 如果总量增加，那么人均产量增加，缺人数变化。
　　(C) If any new coal mines had openedin Tribnia in the past five years, then the increase in output per miner wouldhave been even greater than it actually was. 如果有新矿开业，那么人均产量增加，缺人数变化。
　　(D) If any individual Tribnian coalmine has not increased its output per miner in the past five years, then thatmine's overall output has declined or remained constant. 如果人均没有增加，那么总产出下降或不变，缺乏人数变化。
　　(E) In Tribnia the cost of producing agiven quantity of coal has declined over the past five years.成本不可推测。
　　数学考点一：总量=均量?数量
　　可能出现考点的标志词：per/ totoal
　　我们再做一道
　　2. From 1973 to 1976, total United States consumption of cigarettes increased 3.4 percent, and total sales of chewing tobacco rose 18.0 percent. During the sameperiod, total United States population increased 5.0 percent.
　　If the statements above are true, which of the following conclusions can be properly drawn?
　　(A) United States manufacturers of tobacco products had higher profits in 1976 than in 1973.
　　(B) Per capita consumption of cigarettes in the United States was lower in 1976 than in 1973.
　　(C) The proportion of nonsmokers in the United States population dropped slightly between 1973 and 1976.
　　(D) United States manufacturers of tobacco products realize a lower profit oncigarettes than on chewing tobacco. (E) A large percentage of United States smokers switched from cigarettes to chewing tobacco between 1973 and 1976.
　　答案：B
　　解析：
　　根据问题要求可以判断这依然是一道归纳推理题。在文章描述的过程中我们发现描述的是从1973到1976年的一些变化，对于这些变化的表现较直观的方式是列出表格
　　根据表格内容，对应选项描述，那个选项描述的内容可以被计算且计算结果正确，那这个选项是可以选的。
　　(A) United States manufacturers of tobacco products had higher profits in 1976 than in 1973. 根据文章信息无法推出利润的变化。
　　(B)Per capita consumption of cigarettesin the United States was lower in 1976 than in 1973. Cigarettes/人的变化也可以计算。
　　数学考点二：表格对比
　　可能出现考点的标志词：年份变化，或者比较两个不同的个体
　　根据这两道题目，我们大概知道，数学考点更多的出现在归纳推理题中，而在其他题中也不排除偶尔考察的可能。这两道题目难度虽然不是很大，但很多同学在之前做题的时候往往感觉无从下手，只要知道在所有逻辑题目中常考那些数学考点，然后在做题读文章的时候关注标志词，做好准备，那题目的考点内容也就一目了然，选项自然好选。