本文就概念法和画图法对新GRE数学考试进行解析:
学生总数240,学SCIENCE的是140,学MATH的170,求LEARN MATH BUT NOT SCIENCE的人数?
1)THERE ARE 55 STUDENTS WHO LEARN SCIENCE BUT NOT MATH
2)30 DIDNT SELECT ANY SUBJECT
这种新GRE数学考试题有两种解题方法:
1)、概念法
P=P+P-P
以本题为例,至少学一科的=只学甲科+只学乙科-两科都学
全集=A+B-A交B+非A非B
normal distribution下One standard deviation away from the mean的possibility为68%,Two standard deviation away from the mean的possibility为95%,standard deviation = 10。一种cougar的体长呈正态分布,均值60英寸,问体长在70到80英寸之间的概率?
落在平均值标准方差内的概率
possibility == +=
60-1060-102只落在一边的概率就要除以二,基本上这种题画一条数轴,做几个点会更一目了然一些。
/2 = 13.5
2)、画图法
画两个相交的圆A、B。圆A下写学甲科的总数,圆B下写学乙科的总数;两圆相交的部分写两科都学的数量,不相交的部分写各自只学一门的数量。再在外面画一个大方框,是学生总数,圆外方框内是什么都不学的。这样就一目了然了。
上一篇: 教你如何巧解GRE数学图标题
下一篇: GRE数学机经应该怎么用
体坛英语资讯:Kenyans dominate track events in Osaka
体坛英语资讯:Henin glad to shed Williams sisters fear factor
体坛英语资讯:China surprises world in rowing
体坛英语资讯:China rattle US at Grand Prix womens volleyball
体坛英语资讯:France visit Italy for revenge, England in peril
体坛英语资讯:Hosts hopes up in the air at World Cup
体坛英语资讯:O.J. Simpson faces felony charges
体坛英语资讯:Russia march on to quarters, Israel beat Croatia
体坛英语资讯:Big net cast for Chinese tennis champs
体坛英语资讯:Chinese champ pushes big seed at China Open
体坛英语资讯:Shaq: I will give Yao fancy new wheels as wedding gift
体坛英语资讯:Powell lowers world 100m record to 9.74 sec
体坛英语资讯:Liu, Murofushi spearhead Asian hopes
体坛英语资讯:Yao delivers victory in national team return
体坛英语资讯:26-year-old Universiade athletics record shattered
体坛英语资讯:China confident of derailing talented Brazil
体坛英语资讯:Draft law seeks to find life after sport
体坛英语资讯:Seeded players raise US Open heat
体坛英语资讯:Pierce: Go out and play basketball on street
体坛英语资讯:Rooneys return perfectly timed for United
体坛英语资讯:Another big shots out, coach says worlds lose meaning
体坛英语资讯:Lin wins China derby to book final berth
体坛英语资讯:Coach cares for Liu like a son
体坛英语资讯:Li Yang sets womens 50m backstroke world mark
体坛英语资讯:China suffers 4-0 loss to Brazil
体坛英语资讯:Liu leads Chinese Osaka charge
体坛英语资讯:NBAs spectacular China games just the tip-off
体坛英语资讯:China Open: Gonzalez hard tested, host players out
体坛英语资讯:Hamilton wants to win title on track, not on appeal
体坛英语资讯:Liu Xiang cautious on Osaka prospect