GMAT数学备考资料：练习+讲解（20）
<p> 下面<span word="GMAT">GMAT</span>思为大家整理了<span word="GMAT">GMAT</span>数学备考资料：练习+讲解（20），供考生们参考，以下是详细内容。</p><p> 1、<span word="y">y</span>=<span word="x">x</span>^2+2<span word="qx">qx</span>+<span word="r">r</span>，<span word="X">X</span>轴上有几个交点?</p><p> <span word="q">q</span>^2</p><p> <span word="r">r</span>^2</p><p> 【答案】<span word="A">A</span></p><p> 【思路】<span word="AX">AX</span>^2+<span word="BX">BX</span>+<span word="C">C</span>=0这个方程， <span word="IF">IF</span> <span word="B">B</span>^2-4<span word="AC">AC</span>0，方程有两个不相等的实根;<span word="IF">IF</span> <span word="B">B</span>^2-4<span word="AC">AC</span>=0，方程有两个相等的实根;<span word="IF">IF</span> <span word="B">B</span>^2-4<span word="AC">AC</span>0，方程无解。</p><p> 2、一个班有18个男生，全班有26人选修生物课，问全班人数?</p><p> 男生中选修生物课的有15人;</p><p> 女生人数是没有选修生物课的人数的2倍;</p><p> 【答案】<span word="B">B</span></p><p> 【思路】设全班人数为<span word="X">X</span>，则女生人数为<span word="X">X</span>-18，没选修的人数为<span word="X">X</span>-26，只有条件二可解<span word="X">X</span>。</p><p> 3、<span word="There">There</span> <span word="are">are</span> 100 <span word="students">students</span> <span word="in">in</span> <span word="the">the</span> <span word="class">class</span>. <span word="Each">Each</span> <span word="student">student</span> <span word="must">must</span> <span word="choose">choose</span> <span word="at">at</span> <span word="least">least</span> <span word="one">one</span> <span word="course">course</span> <span word="of">of</span> <span word="English">English</span>, <span word="French">French</span>, <span word="and">and</span> <span word="German">German</span>. <span word="But">But</span> <span word="no">no</span> <span word="student">student</span> <span word="can">can</span> <span word="choose">choose</span> <span word="all">all</span> <span word="the">the</span> <span word="three">three</span> <span word="class">class</span>. <span word="There">There</span> <span word="are">are</span> 30 <span word="students">students</span> <span word="learn">learn</span> <span word="E">E</span>, <span word="and">and</span> 60 <span word="students">students</span> <span word="learn">learn</span> <span word="French">French</span>, <span word="and">and</span> 15 <span word="students">students</span> <span word="learning">learning</span> <span word="German">German</span> <span word="also">also</span> <span word="learn">learn</span> <span word="English">English</span>. <span word="How">How</span> <span word="many">many</span> <span word="students">students</span> <span word="learn">learn</span> <span word="German">German</span>?</p><p> 【答案】25</p><p> 【思路】100-30-60+15=25，学<span word="E">E</span>不学<span word="F">F</span>，也就是<span word="E">E</span>与<span word="F">F</span>的交集为0，同理<span word="F">F</span>与<span word="G">G</span>的交集也为0，那么只有<span word="E">E</span>与<span word="G">G</span>有交集为15，则学<span word="E">E</span>学<span word="G">G</span>的人为60+30-15，现在要求<span word="F">F</span>只要把学<span word="E">E</span>学<span word="G">G</span>的减掉即可。</p><p> 4、<span word="Every">Every</span> <span word="internal">internal</span> <span word="angle">angle</span> <span word="in">in</span> <span word="a">a</span> <span word="polygon">polygon</span> <span word="is">is</span> <span word="less">less</span> <span word="than">than</span> 180. <span word="How">How</span> <span word="much">much</span> <span word="is">is</span> <span word="the">the</span> <span word="average">average</span> <span word="internal">internal</span> <span word="angle">angle</span> <span word="for">for</span> <span word="a">a</span> <span word="polygon">polygon</span>:</p>
页:
[1]