新gre数学考点介绍：排列
<p> 新<span word="gre">gre</span>考试实施以来，不仅对写作部分茫然不知所措，就连我们所擅长的数学也甚是担忧，相信这其中的原因还是由于考生在新<span word="gre">gre</span>数学复习时没有把基础打牢。如果新版<span word="gre">gre</span>数学基本考点都没有复习到，如何能拿到分数呢?所以说，想要新版<span word="gre">gre</span>数学考好，复习的时候一定要把基本概念和重要考点都弄扎实。</p><p> <span word="Permutation">Permutation</span> <span word="of">of</span> <span word="Objects">Objects</span></p><p> <span word="The">The</span> <span word="number">number</span> <span word="of">of</span> <span word="ways">ways</span> <span word="n">n</span> <span word="distinct">distinct</span> <span word="objects">objects</span> <span word="can">can</span> <span word="be">be</span> <span word="ordered">ordered</span> <span word="is">is</span> <span word="n">n</span>!.</p><p> <span word="Example">Example</span>:</p><p> <span word="Number">Number</span> <span word="of">of</span> <span word="ways">ways</span> 6 <span word="people">people</span> <span word="can">can</span> <span word="from">from</span> <span word="a">a</span> <span word="queue">queue</span> <span word="is">is</span> 6!.</p><p> <span word="Number">Number</span> <span word="of">of</span> <span word="ways">ways</span> 5 <span word="different">different</span> <span word="cars">cars</span> <span word="can">can</span> <span word="be">be</span> <span word="parked">parked</span> <span word="in">in</span> 5 <span word="parking">parking</span> <span word="spaces">spaces</span> <span word="is">is</span> 5!.</p><p> <span word="Remember">Remember</span>:</p><p> <span word="This">This</span> <span word="does">does</span> <span word="not">not</span> <span word="apply">apply</span> <span word="if">if</span> <span word="there">there</span> <span word="are">are</span> <span word="identical">identical</span> <span word="objects">objects</span> <span word="or">or</span> <span word="ordering">ordering</span> <span word="does">does</span> <span word="not">not</span> <span word="matter">matter</span>.</p><p> <span word="Permutation">Permutation</span> <span word="with">with</span> <span word="Selection">Selection</span></p><p> <span word="The">The</span> <span word="number">number</span> <span word="of">of</span> <span word="ways">ways</span> <span word="n">n</span> <span word="objects">objects</span> <span word="drawn">drawn</span> <span word="from">from</span> <span word="a">a</span> <span word="collection">collection</span> <span word="of">of</span> <span word="m">m</span> <span word="distinct">distinct</span> <span word="objects">objects</span> <span word="can">can</span> <span word="be">be</span> <span word="ordered">ordered</span> <span word="is">is</span> <span word="m">m</span>!/!.</p><p> <span word="Example">Example</span>:</p><p> <span word="Number">Number</span> <span word="of">of</span> <span word="ways">ways</span> <span word="a">a</span> <span word="queue">queue</span> <span word="of">of</span> <span word="length">length</span> 3 <span word="can">can</span> <span word="be">be</span> <span word="formed">formed</span> <span word="from">from</span> <span word="a">a</span> <span word="group">group</span> <span word="of">of</span> 5 <span word="people">people</span> <span word="is">is</span> 5!/!=5!/2!=543=60.</p><p> <span word="Number">Number</span> <span word="of">of</span> <span word="possible">possible</span> <span word="top">top</span> <span word="ten">ten</span> <span word="list">list</span> <span word="for">for</span> 150 <span word="movies">movies</span> <span word="is">is</span> 150!/!.</p><p> <span word="Remember">Remember</span>:</p><p> <span word="This">This</span> <span word="does">does</span> <span word="not">not</span> <span word="apply">apply</span> <span word="if">if</span> <span word="there">there</span> <span word="are">are</span> <span word="identical">identical</span> <span word="objects">objects</span> <span word="or">or</span> <span word="ordering">ordering</span> <span word="does">does</span> <span word="not">not</span> <span word="matter">matter</span>：</p><p> 由于美国数学基础教育的难度增加导致数学考试越来越难，但新<span word="gre">gre</span>数学复习考点都是高中时候学到的知识点，考生不要过于紧张，把基本概念弄明白，再记住一些新版<span word="gre">gre</span>数学必备的词汇，那么相信新版<span word="gre">gre</span>数学应该没有问题。</p>
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