{"id":7088,"date":"2020-03-09T06:00:30","date_gmt":"2020-03-09T11:00:30","guid":{"rendered":"https:\/\/grockit.com\/blog\/gre\/?p=547"},"modified":"2020-09-11T20:40:05","modified_gmt":"2020-09-11T20:40:05","slug":"quantitative-elimination-strategies-gmat","status":"publish","type":"post","link":"https:\/\/www.qa.kaptest.com\/study2\/gmat\/quantitative-elimination-strategies-gmat\/","title":{"rendered":"GMAT Quantitative Elimination Strategies"},"content":{"rendered":"<p>As with all multiple choice tests, there is more to strategy than simply trying to answer the question. Answer choices are gifts that test-takers must take advantage of. Every effective test-taker must understand the strategies used to efficiently\u00a0eliminate wrong answer choices. These will help you save time, and more importantly, they may lead you to the correct answer even when you&#8217;re not as\u00a0confident about the material as you would like to be.<br \/>\n&nbsp;<br \/>\n\t<div  style='background:#222222;color:#ffffff;border-color:#222222;' class='av_promobox  avia-button-no   avia-builder-el-0  el_before_av_promobox  avia-builder-el-first '>\t\t<div class='avia-promocontent'><\/p>\n<h3><span style=\"color: #ceb3fc\">Elimination Strategy<\/span><\/h3>\n<h3><span style=\"color: #ffffff\">When you are asked to find the least\/greatest number, eliminate the least\/greatest number from the answer choices.<\/span><\/h3>\n<p><span style=\"color: #b4b4b4\">While we could never say that this rule works 100 percent of the time, it certainly works most of the time, and it follows the test-maker&#8217;s logic. When test-takers guess on these problems, they tend to guess the extreme answer choice (i.e. if asked for the greatest, they&#8217;ll pick the greatest). Test makers catch on to this, and as a result, they rarely allow that expected choice to be the answer.<\/span><\/p>\n<h3><span style=\"color: #ffffff\">Sample Question<\/span><\/h3>\n<p>1. What is the maximum number of points common to the intersection of a square and a triangle if no two sides coincide?<br \/>\na. 4<br \/>\nb. 5<br \/>\nc. 6<br \/>\nd. 8<br \/>\ne. 9<\/p>\n<h3><span style=\"color: #ffffff\">Sample Question Explanation<\/span><\/h3>\n<h3><span style=\"color: #ffffff\"><span style=\"color: #1ac085\">The correct answer is C.<\/span><\/span><\/h3>\n<p><span style=\"color: #b4b4b4\">According to the strategy, we can eliminate 9. In fact, c is the answer (this question becomes more manageable if we draw it out).<\/span><\/p>\n<\/div><\/div><br \/>\n\t<div  style='background:#222222;color:#ffffff;border-color:#222222;' class='av_promobox  avia-button-no   avia-builder-el-1  el_after_av_promobox  el_before_av_heading '>\t\t<div class='avia-promocontent'><\/p>\n<h3><span style=\"color: #ceb3fc\">Elimination Strategy<\/span><\/h3>\n<h3><span style=\"color: #ffffff\">On higher-difficulty problems, often eliminate the answer choice &#8216;not enough information&#8217; and choices that merely repeat numbers from the problem.<\/span><\/h3>\n<p><span style=\"color: #b4b4b4\">Many students tend to go for the &#8216;not enough information&#8217; choice when they are out of time, and test makers will rarely let you get away with no calculation for a difficult problem.<\/span><\/p>\n<h3><span style=\"color: #ffffff\">Sample Question<\/span><\/h3>\n<p>If the sum of <em>x<\/em> and 20 is 8 more than the difference of 10 and <em>y<\/em>, what is the value of <em>x<\/em> + <em>y<\/em>?<br \/>\na. -2<br \/>\nb. 8<br \/>\nc. 9<br \/>\nd. 28<br \/>\ne. not enough information<\/p>\n<h3><span style=\"color: #ffffff\">Sample Question Explanation<\/span><\/h3>\n<h3><span style=\"color: #ffffff\"><span style=\"color: #1ac085\">The correct answer is A.<\/span><\/span><\/h3>\n<p>If this type of problem is giving you trouble, and you have no choice but to guess, you should be skeptical of answer choices b and e. E, as we saw earlier, is a &#8216;not enough information,&#8217; and b gets the number &#8216;8&#8217; from the question. Again, these are not hard and fast rules, but you will increase your chances by avoiding these answers if you must guess.<br \/>\nLet&#8217;s see if we can answer it. This is a problem that needs to be converted into mathematical notation:<br \/>\n<em>x<\/em> + 20 = 8 + (10 &#8211; <em>y<\/em>)<br \/>\n<em>x<\/em> + 12 = 10 &#8211;\u00a0<em>y<\/em><br \/>\n<em>x<\/em> + <em>y\u00a0<\/em>= 10 &#8211; 12<br \/>\n<em>x<\/em> + <em>y\u00a0<\/em>= -2<br \/>\nRemember, there is no substitute for knowing the math, but you also want to increase your chances on the toughest problems.<\/p>\n<\/div><\/div><br \/>\n<div  style='padding-bottom:10px; ' class='av-special-heading av-special-heading-h3    avia-builder-el-2  el_after_av_promobox  el_before_av_promobox  '><h3 class='av-special-heading-tag '  itemprop=\"headline\"  >Practice Questions<\/h3><div class='special-heading-border'><div class='special-heading-inner-border' ><\/div><\/div><\/div><br \/>\nNow, let&#8217;s look at some examples of problems that would benefit from these elimination strategies, and then we&#8217;ll properly solve them.<br \/>\n\t<div  style='background:#ffffff;color:#000000;border-color:#333333;' class='av_promobox  avia-button-no   avia-builder-el-3  el_after_av_heading  el_before_av_toggle_container '>\t\t<div class='avia-promocontent'><\/p>\n<h3>Question #1<\/h3>\n<p>Let <em>p<\/em> stand for the product of the first 5 positive integers. What is the greatest possible value of m if <em>p<\/em>\/10^<em>m<\/em> is an integer?<br \/>\na. 1<br \/>\nb. 2<br \/>\nc. 3<br \/>\nd. 5<br \/>\ne. 10<\/p>\n<\/div><\/div><br \/>\n<div  class=\"togglecontainer   toggle_close_all  avia-builder-el-4  el_after_av_promobox  el_before_av_heading \" >\n<section class=\"av_toggle_section\"  itemscope=\"itemscope\" itemtype=\"https:\/\/schema.org\/BlogPosting\" itemprop=\"blogPost\"  >    <div role=\"tablist\" class=\"single_toggle\" data-tags=\"{All} \"  >        <p data-fake-id=\"#toggle-id-1\" class=\"toggler \"  itemprop=\"headline\"    role=\"tab\" tabindex=\"0\" aria-controls=\"toggle-id-1\">Explanation<span class=\"toggle_icon\" >        <span class=\"vert_icon\"><\/span><span class=\"hor_icon\"><\/span><\/span><\/p>        <div id=\"toggle-id-1\" class=\"toggle_wrap \"  >            <div class=\"toggle_content invers-color \"  itemprop=\"text\"   ><h3><span style=\"color: #1ac085\">THE CORRECT ANSWER IS A.<\/span><\/h3>\n<p>First, since we are to find the greatest value of m, we should eliminate E, which is the greatest available number.<br \/>\nNow, let&#8217;s answer the question. Since we are looking for the largest number, start with the greatest number remaining and work toward the smallest number. The first number that works will be the answer.<br \/>\nLet m=3. Then <em>p<\/em>\u00a0\/ 10^<em>m<\/em> = 1*2*3*4*5 \/ 10^3 = 120\/100 = 3\/25 (not an integer).<br \/>\nNext, let&#8217;s try m=2. <em>p<\/em>\u00a0\/ 10^<em>m<\/em> = 1*2*3*4*5 \/ 10^2 = 120 \/ 100 = 6\/5. not an integer.<br \/>\nNow, let <em>m<\/em> = 1. <i>p<\/i>\u00a0\/ 10^<em>m<\/em> = 120\/ 10 = 12. There\u2019s our integer, and our answer is A.<\/p>\n            <\/div>        <\/div>    <\/div><\/section>\n<\/div><br \/>\n&nbsp;<br \/>\n<div  style='padding-bottom:10px; ' class='av-special-heading av-special-heading-h4  blockquote modern-quote  avia-builder-el-5  el_after_av_toggle_container  el_before_av_heading  '><h4 class='av-special-heading-tag '  itemprop=\"headline\"  >Question 2<\/h4><div class='special-heading-border'><div class='special-heading-inner-border' ><\/div><\/div><\/div><br \/>\n<em>After being marked down 20 percent, a calculator sells for $10. The original selling price was<\/em><br \/>\n<em> a. $20<\/em><br \/>\n<em> b. $12.50<\/em><br \/>\n<em> c. $12<\/em><br \/>\n<em> d. $9<\/em><br \/>\n<em> e. $7<\/em><br \/>\nFirst, we can say that twenty dollars is just too large. The discount was only 20 percent, so eliminate A. Both D and E are impossible since they are less than the selling price. 12 is a kind of eye catcher since 20 percent of 10 is 2 and 10+2 = 12. B seems the most likely answer based on elimination strategies, but let&#8217;s do the math just to make sure.<br \/>\nTo answer the problem, it&#8217;s easiest to convert the information into an equation. Why not convert the phrase &#8220;being marked down 20 percent&#8221; to &#8220;.8x, since taking 20 percent off is the same thing as paying 80 percent of the price:<br \/>\n.8x = 10<br \/>\nx= 10\/ .8<br \/>\nx=12.5<br \/>\n<div  style='padding-bottom:10px; ' class='av-special-heading av-special-heading-h4  blockquote modern-quote  avia-builder-el-6  el_after_av_heading  el_before_av_heading  '><h4 class='av-special-heading-tag '  itemprop=\"headline\"  >Question 3<\/h4><div class='special-heading-border'><div class='special-heading-inner-border' ><\/div><\/div><\/div><br \/>\n<em>The distance between cities A and B is 120 miles. A car travels from A to B at 60 miles per hour and returns from B to A along the same route at 40 miles per hour. What is the average speed of the round trip?<\/em><br \/>\n<em> a. 48<\/em><br \/>\n<em> b. 50<\/em><br \/>\n<em> c. 52<\/em><br \/>\n<em> d. 56<\/em><br \/>\n<em> e. 58<\/em><br \/>\nFirst, we can eliminate 50 (the mere average of 40 and 60) since that would be too simple a calculation. The average must be closer to 40 than to 60 because the car travels for a longer time at 40 mph. But 48 is the only number given that is closer to 40 than to 60. Based on common sense and elimination, the answer is A.<br \/>\nHere is how to calculate the problem:<br \/>\nRemember that average speed = total distance \/ total time.<br \/>\nA car traveling at 40 mph will cover 120 miles in 3 hours. And a car traveling at 60 mph will cover the same 120 miles in 2 hours. So the total traveling time is 5 hours. Thus, for the round trip, the average speed is (120 + 120) \/ 5 =48<br \/>\n<div  style='padding-bottom:10px; ' class='av-special-heading av-special-heading-h4  blockquote modern-quote  avia-builder-el-7  el_after_av_heading  el_before_av_sidebar  '><h4 class='av-special-heading-tag '  itemprop=\"headline\"  >Question 4<\/h4><div class='special-heading-border'><div class='special-heading-inner-border' ><\/div><\/div><\/div><br \/>\n<em>If w is 10 percent less than x, and y is 30 percent less than z, then wy is what percent less than xz?<\/em><br \/>\n<em> a. 10 %<\/em><br \/>\n<em> b. 20%<\/em><br \/>\n<em> c. 37%<\/em><br \/>\n<em> d. 40%<\/em><br \/>\n<em> e. 100%<\/em><br \/>\nWe should be skeptical of A since it repeats the number 10 from the problem. We can also be skeptical of B, D, and E since they can be derived from simple calculations.<br \/>\nFor example:<br \/>\n20= 30-10.<br \/>\n40=30+10.<br \/>\n100 = 10 * 10.<br \/>\nElimination strategies point to c as the answer, but let&#8217;s make sure it&#8217;s correct.<br \/>\nThis is a simple translation problem:<br \/>\nThe expression \u201cw is 10 percent less than x\u201d can be written as:<br \/>\nw = x &#8211; .1x<br \/>\nw=.9x<br \/>\nThe same goes for the relationship between y and z:<br \/>\ny =z-.3z<br \/>\ny=.7z<br \/>\nMultiply the two expressions, and you get:<br \/>\nwy= (.9x) (.7z) = .63 xz<br \/>\nNow we must translate .63xz in order to express \u201cwy is what percent less than xz:\u201d<br \/>\nwy = xz &#8211; .37xz<br \/>\nThis means that wy is 37 percent less than xz.<\/p>\n<p class=\"p1\"><div  class='avia-builder-widget-area clearfix  avia-builder-el-8  el_after_av_heading  avia-builder-el-last '><div id=\"text-76\" class=\"widget clearfix widget_text\">\t\t\t<div class=\"textwidget\"><p><span data-sumome-listbuilder-embed-id=\"70f62512b89832cc8e7fcd96b9d03245c2794cf0b7170fa257f26acec72436d9\"><\/span><\/p>\n<\/div>\n\t\t<\/div><div id=\"text-77\" class=\"widget clearfix widget_text\">\t\t\t<div class=\"textwidget\"><p><span data-sumome-listbuilder-embed-id=\"71160db829b51adcc3539815988485f372b020407413c2957efe50cfe72ea639\"><\/span><\/p>\n<\/div>\n\t\t<\/div><\/div><\/p>\n","protected":false},"excerpt":{"rendered":"<p>As with all multiple choice tests, there is more to strategy than simply trying to answer the question. Answer choices are gifts that test-takers must take advantage of. Every effective test-taker must understand the strategies used to efficiently\u00a0eliminate wrong answer choices. These will help you save time, and more importantly, they may lead you to [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":28916,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[55],"tags":[56,80],"class_list":["post-7088","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-gmat","tag-gmat","tag-gmat-quantitative"],"_links":{"self":[{"href":"https:\/\/www.qa.kaptest.com\/study2\/wp-json\/wp\/v2\/posts\/7088","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.qa.kaptest.com\/study2\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.qa.kaptest.com\/study2\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.qa.kaptest.com\/study2\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.qa.kaptest.com\/study2\/wp-json\/wp\/v2\/comments?post=7088"}],"version-history":[{"count":0,"href":"https:\/\/www.qa.kaptest.com\/study2\/wp-json\/wp\/v2\/posts\/7088\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.qa.kaptest.com\/study2\/wp-json\/wp\/v2\/media?parent=7088"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.qa.kaptest.com\/study2\/wp-json\/wp\/v2\/categories?post=7088"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.qa.kaptest.com\/study2\/wp-json\/wp\/v2\/tags?post=7088"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}