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<\/p>\n<\/p>\n
Welcome to the third installment of Fast Math for the Executive Assessment! If you\u2019re just joining us now, you might want to go back to the first part<\/a> and work your way back here.<\/span><\/p>\n I have another problem for you from the official free practice set (this one is labeled #4 in the PS set on the Executive Assessment website, as of September 2017):<\/span><\/p>\n \u201cThe regular price per can of a certain brand of soda is $0.40. If the regular price per can is discounted 15 percent when the soda is purchased in 24-can cases, what is the price of 72 cans of this brand of soda purchased in 24-can cases?<\/span><\/p>\n \u201c(A) $16.32<\/span><\/p>\n \u201c(B) $18.00<\/span><\/p>\n \u201c(C) $21.60<\/span><\/p>\n \u201c(D) $24.48<\/span><\/p>\n \u201c(E) $28.80\u201d<\/span><\/p>\n What did you think about this problem?<\/span><\/p>\n I found it pretty annoying. <\/span>\u263a<\/span> I mean, sure, I didn\u2019t find it crazy hard to find the 15% discount off of $0.40:<\/span><\/p>\n 10% of 0.40 is 0.04\u2026<\/span> And then I want to buy 72 cans, so it\u2019s just (72)(0.34)\u2026<\/span>aaagh,<\/span><\/i> but I don\u2019t have a calculator<\/span><\/i>.<\/span><\/p>\n I refuse to do that out the long way. Seriously! There\u2019s got to be an easier way.<\/span><\/p>\n Picture this: You\u2019re standing in the convenience store. You want to buy this soda. You\u2019ve just figured out that it\u2019s going to cost you $0.34 a can\u2026and you know you want 72 cans\u2026but you don\u2019t have a calculator on you (your phone died) and you don’t even have pen and paper. Also, you forgot your credit card. (It\u2019s been a long day.) <\/span><\/p>\n So how are you going to figure out whether you have enough cash on you to buy all 72 cans?<\/span><\/p>\n That\u2019s not a rhetorical question. Close your eyes, picture yourself there, and try to figure out what you\u2019d do.<\/span><\/p>\n Thinking?<\/span><\/p>\n Thinking?<\/span><\/p>\n Okay, here\u2019s my idea. In the real world, I wouldn\u2019t literally need to calculate to the penny\u2014I\u2019d just need to estimate to make sure I have <\/span>enough<\/span><\/i> cash. But this is a math test and the answers are down to the penny\u2026so don\u2019t I have to calculate exactly here?<\/span><\/p>\n Glance at the answers.<\/span><\/p>\n If the answers had been of the variety $10.01, $10.02, $10.03\u2026, then yes, I\u2019d have to calculate to the penny. But they\u2019re not. They\u2019re each at least a couple of dollars apart, so I can estimate. How?<\/span><\/p>\n Let\u2019s see. It\u2019s going to cost me $0.34 to buy one can. How many could I buy for a dollar?<\/span><\/p>\n I can get 3 cans (basically\u2014technically, it\u2019ll cost me $1.02 for 3 cans, but close enough!). So 3 cans for $1\u2026how many do I want again? Oh yeah, 72 cans. So that\u2019s going to cost me about 72 \/ 3 = $24.<\/span><\/p>\n Oh. Look at the answers. There\u2019s only one that\u2019s close\u2014answer (D). Done!<\/span><\/p>\n You can also, by the way, do this same estimation from the math I set up before I got frustrated by my lack of a calculator: (72)(0.34). Just look at it in a different way, now that you\u2019ve realized you can estimate. Since 0.34 is about 1\/3, you’re just taking about one-third of 72…it\u2019s the same math! $24.<\/span><\/p>\n What we just did is classic back-of-the-envelope math. You don\u2019t need an exact number\u2014you just need a quick-and-dirty, good-enough estimate. We certainly weren\u2019t allowed to do that on math tests in school, but the Executive Assessment is <\/span>not<\/span><\/i> a math test. <\/span><\/p>\n Well, yes, it is, somewhat. But not in the way that you\u2019re used to from school. We do have to know various math formulas and rules, but the Executive Assessment is really mostly interested in how well you can reason about math. After all, in the real world, you\u2019re never going to be forced to do math on paper without the benefit of Excel or a calculator. But you are going to need to be able to think about mathematical concepts and draw conclusions\u2014not in the \u201cwhat\u2019s the answer to this math problem\u201d sense, but in a \u201cwhat should we do about this problem that our division is facing?\u201d sense.<\/span><\/p>\n So, while the Executive Assessment looks a whole lot like a traditional math test, it really isn\u2019t at all. Most of the time, you can get to the answer through a combination of strategic approaches, like the back-of-the-envelope approach discussed above. That\u2019s what you\u2019re looking to learn and practice as you study for this exam.<\/span><\/p>\n (1) You often don\u2019t need to calculate exact values. Look for opportunities to estimate and do back-of-the-envelope calculations wherever possible.<\/span><\/p>\n (2) If the numbers in the problem or answers (or both!) seem annoying, there\u2019s probably an opportunity to estimate somewhere. Also, get in the habit of glancing at the answers to see how far apart they are (when they\u2019re just plain numbers)\u2014the farther apart they are, the better the opportunity to estimate.<\/span><\/p>\n (3) Turn that knowledge into Know the Code flash cards:<\/span><\/p>\n Can\u2019t get enough of Stacey\u2019s GMAT mastery? Attend the first session of one of\u00a0her upcoming GMAT courses<\/a>\u00a0absolutely free, no strings attached. Seriously.<\/strong><\/em><\/p>\n Welcome to the third installment of Fast Math for the Executive Assessment! If you\u2019re just joining us now, you might want to go back to the first part and work your way back here.<\/p>\n","protected":false},"author":6,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[928,52900,53128,873,18,2,4,8],"tags":[53022],"yst_prominent_words":[58107,56340,55481,58108,57243,55477,53997],"class_list":["post-15998","post","type-post","status-publish","format-standard","hentry","category-business-mindset","category-business-school","category-executive-assessment","category-for-current-studiers","category-manhattan-gmat-blog-fdp","category-how-to-study","category-mba-b-school","category-quant-on-gmat","tag-fast-math"],"_links":{"self":[{"href":"https:\/\/www.manhattanprep.com\/gmat\/wp-json\/wp\/v2\/posts\/15998","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.manhattanprep.com\/gmat\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.manhattanprep.com\/gmat\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.manhattanprep.com\/gmat\/wp-json\/wp\/v2\/users\/6"}],"replies":[{"embeddable":true,"href":"https:\/\/www.manhattanprep.com\/gmat\/wp-json\/wp\/v2\/comments?post=15998"}],"version-history":[{"count":2,"href":"https:\/\/www.manhattanprep.com\/gmat\/wp-json\/wp\/v2\/posts\/15998\/revisions"}],"predecessor-version":[{"id":16012,"href":"https:\/\/www.manhattanprep.com\/gmat\/wp-json\/wp\/v2\/posts\/15998\/revisions\/16012"}],"wp:attachment":[{"href":"https:\/\/www.manhattanprep.com\/gmat\/wp-json\/wp\/v2\/media?parent=15998"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.manhattanprep.com\/gmat\/wp-json\/wp\/v2\/categories?post=15998"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.manhattanprep.com\/gmat\/wp-json\/wp\/v2\/tags?post=15998"},{"taxonomy":"yst_prominent_words","embeddable":true,"href":"https:\/\/www.manhattanprep.com\/gmat\/wp-json\/wp\/v2\/yst_prominent_words?post=15998"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}![\"Manhattan](\"https:\/\/www.manhattanprep.com\/gmat\/wp-content\/uploads\/sites\/18\/2018\/06\/sk-444-image-2.png\")
<\/p>\n
\n<\/span>another 5% is half of that, or 0.02\u2026<\/span>
\n<\/span>so the discount is $0.06\u2026<\/span>
\n<\/span>and the discounted price is $0.34<\/span><\/p>\nKey Takeaways for Executive Assessment Fast Math<\/b><\/h4>\n
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<\/p>\n* Executive Assessment questions courtesy of the Graduate Management Admissions Council. Usage of this question does not imply endorsement by GMAC.\u00a0?<\/h5>\n
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\n![\"stacey-koprince\"](\"https:\/\/cdn2.manhattanprep.com\/gmat\/wp-content\/uploads\/sites\/18\/2015\/06\/stacey-koprince-150x150.png\")
<\/a>Stacey Koprince<\/a>\u00a0is a Manhattan Prep instructor based in Montreal, Canada and Los Angeles, California.<\/strong>\u00a0Stacey has been teaching the GMAT, GRE, and LSAT for more than 15 years and is one of the most well-known instructors in the industry. Stacey loves to teach and is absolutely fascinated by standardized tests.\u00a0Check out Stacey\u2019s upcoming GMAT courses here<\/a>.<\/em><\/p>\n","protected":false},"excerpt":{"rendered":"