![\"Manhattan](\"http:\/\/www.manhattanprep.com\/gre\/wp-content\/uploads\/sites\/19\/2017\/03\/3-8-17-social-1.png\")
<\/p>\n<\/p>\n
Did you know that you can attend the first session of any of our online or in-person GRE courses absolutely free? We\u2019re not kidding! <\/i><\/b>Check out our upcoming courses here<\/i><\/b><\/a>.<\/i><\/b><\/p>\n <\/i><\/b>You know what I love about GRE Discrete Quant problems? Specifically, multiple-choice Discrete Quant? <\/span>The answer choices<\/span><\/i>. Think about it: out of the infinite number of numbers in the universe, the GRE has already narrowed it down to just <\/span>five possibilities<\/span><\/i>. They\u2019ve done almost all of the work for you. And that makes Discrete Quant a huge opportunity for People Who Hate Math. <\/span><\/p>\n It\u2019s a lot easier to <\/span>check whether someone else\u2019s answer is correct<\/span><\/i> than it is to solve a problem from scratch. For example, imagine trying to figure out exactly what you need to eat each day in order to lose a pound per week. It would be difficult and time-consuming to create a plan on your own. However, what if a nutritionist just gave you a meal plan and told you to follow it? Even if you didn\u2019t know how to work out the exact answer on your own, it would be pretty easy to determine whether the nutritionist\u2019s answer was correct. You\u2019d just follow their meal plan for a couple of weeks and see what happened. If it worked, you\u2019d know that you\u2019d found the right answer, without working it out on your own. In fact, you wouldn\u2019t even need to know anything about nutrition at all to use this approach. <\/span><\/p>\n There are thousands of different possible diets, but only five possible answers to a multiple-choice DQ problem. And it takes a couple of seconds, not a couple of weeks, to decide whether a particular answer is right. The GRE\u2019s already told you that one of those five answers is the right one. So, why not just test each of them until you find one that works? It\u2019s sometimes much easier than working out the answer on your own \u2013 and you can get away with a lot less math. <\/span><\/p>\n This style of problem solving is called <\/span>backsolving<\/b>. In order to use backsolving on a GRE math problem, a few conditions need to be met. Here they are:<\/span><\/p>\n That\u2019s it. If a problem meets those criteria, you can backsolve! <\/span><\/p>\n Backsolving is very similar to \u2018checking your work\u2019. When you decide to backsolve, imagine that I\u2019ve just told you what <\/span>I<\/span><\/i> think the right answer is. Now, you need to determine whether I was right. Let\u2019s try it on an example problem from the 5lb. Book of GRE Practice Problems. <\/span><\/p>\n If 150 were increased by 60% and then decreased by y percent, the result would be 192. What is the value of y?<\/span><\/p>\n (A) 20 Suppose I told you that the answer was 28, and you wanted to check my work. You\u2019d turn to your calculator. You\u2019d take 150, increase it by 60%, then decrease it by 28%. If the result came out to 192, you\u2019d know that I was right. If it didn\u2019t, that would mean I\u2019d done something wrong. <\/span><\/p>\n 150, increased by 60%, is 240. <\/span><\/p>\n 240, decreased by 28%, is 172.8. <\/span><\/p>\n That\u2019s not 192, so I was definitely wrong. <\/span><\/p>\n You don\u2019t know the right answer, yet \u2013 but that doesn\u2019t matter! The right answer must be there among the five answer choices, and you\u2019ve just eliminated one of them. That leaves, at most, four more to check. Should we try an answer choice that\u2019s higher or lower than 28? <\/span><\/p>\n If you said \u2018lower\u2019, you\u2019re correct. The answer we got was too small, which means we decreased 240 by too large of a percentage. The only answer choice smaller than 28 is (A) 20, so that one must be correct. But if you have the time, and you don\u2019t totally trust yourself, plug those numbers into your calculator to double check:<\/span><\/p>\n 150, increased by 60%, is 240. <\/span><\/p>\n 240, decreased by 20%, is 192. <\/span><\/p>\n 20% is the right answer!<\/span><\/p>\n If you\u2019ve ever \u2018checked your work\u2019 by plugging an answer back into the problem, you already know how to backsolve. Try it out on these mini problems. They only have two answers each \u2013 your job is to figure out which one is right and which one is wrong, <\/span>without<\/span><\/i> creating equations.<\/span><\/p>\n Think you\u2019ve got it? Open up the 5lb. Book of GRE Practice Problems<\/a> and try it out on some Discrete Quant problems from the Percents, Word Problems, or Ratios chapters. Remember, you don\u2019t have to do GRE math problems in the same way you solved these problems in middle-school math class. If a solution gets you to the right answer quickly, it\u2019s a good solution \u2013 so stay flexible and explore all of your options. ?<\/span><\/p>\n Answers: 17.5, 300, $42<\/span><\/i><\/p>\n Want more guidance from our GRE gurus? You can attend the first session of any of our online or in-person GRE courses absolutely free! We\u2019re not kidding. <\/i><\/b>Check out our upcoming courses here<\/i><\/b><\/a>.<\/i><\/b><\/p>\n Chelsey Cooley<\/a> Did you know that you can attend the first session of any of our online or in-person GRE courses absolutely free? We\u2019re not kidding! Check out our upcoming courses here. You know what I love about GRE Discrete Quant problems? Specifically, multiple-choice Discrete Quant? The answer choices. Think about it: out of the infinite number […]<\/p>\n","protected":false},"author":127,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[2,474284,921840,421,6,7,9,733445],"tags":[1362367,1362366,151],"yst_prominent_words":[],"class_list":["post-10097","post","type-post","status-publish","format-standard","hentry","category-challenge-problems","category-current-studiers","category-gre-prep-2","category-gre-quant-2","category-gre-strategies","category-how-to-study","category-math-gre-strategies","category-study-tips-2","tag-backsolving","tag-gre-discrete-quant","tag-gre-math"],"_links":{"self":[{"href":"https:\/\/www.manhattanprep.com\/gre\/wp-json\/wp\/v2\/posts\/10097","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.manhattanprep.com\/gre\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.manhattanprep.com\/gre\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.manhattanprep.com\/gre\/wp-json\/wp\/v2\/users\/127"}],"replies":[{"embeddable":true,"href":"https:\/\/www.manhattanprep.com\/gre\/wp-json\/wp\/v2\/comments?post=10097"}],"version-history":[{"count":4,"href":"https:\/\/www.manhattanprep.com\/gre\/wp-json\/wp\/v2\/posts\/10097\/revisions"}],"predecessor-version":[{"id":10126,"href":"https:\/\/www.manhattanprep.com\/gre\/wp-json\/wp\/v2\/posts\/10097\/revisions\/10126"}],"wp:attachment":[{"href":"https:\/\/www.manhattanprep.com\/gre\/wp-json\/wp\/v2\/media?parent=10097"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.manhattanprep.com\/gre\/wp-json\/wp\/v2\/categories?post=10097"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.manhattanprep.com\/gre\/wp-json\/wp\/v2\/tags?post=10097"},{"taxonomy":"yst_prominent_words","embeddable":true,"href":"https:\/\/www.manhattanprep.com\/gre\/wp-json\/wp\/v2\/yst_prominent_words?post=10097"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}
\n\n
\n<\/span>(B) 28
\n<\/span>(C) 32
\n<\/span>(D) 72
\n<\/span>(E) 80<\/span><\/p>\n\n
\n
\n![\"Chelsey](\"https:\/\/cdn2.manhattanprep.com\/gre\/wp-content\/uploads\/sites\/19\/2015\/11\/chelsey-cooley-150x150.jpg\" "\\"Chelsey")
<\/a> is a Manhattan Prep instructor based in Seattle, Washington.<\/strong>\u00a0<\/em><\/i><\/b>Chelsey always followed her heart when it came to her education. Luckily, her heart led her straight to the perfect background for GMAT and GRE teaching: she has undergraduate degrees in mathematics and history, a master\u2019s degree in linguistics, a 790 on the GMAT, and a perfect 170\/170 on the GRE.\u00a0<\/em><\/i>Check out Chelsey\u2019s upcoming GRE prep offerings here<\/a>.<\/em><\/i><\/p>\n","protected":false},"excerpt":{"rendered":"