{"id":4686,"date":"2010-10-13T10:31:12","date_gmt":"2010-10-13T18:31:12","guid":{"rendered":"https:\/\/gmatclub.com\/blog\/?p=4686"},"modified":"2010-10-13T10:31:12","modified_gmt":"2010-10-13T18:31:12","slug":"veritas-prep-gmat-tips-changing-the-way-you-think-about-change-problems","status":"publish","type":"post","link":"https:\/\/gmatclub.com\/blog\/veritas-prep-gmat-tips-changing-the-way-you-think-about-change-problems\/","title":{"rendered":"Veritas Prep GMAT Tips: Changing the Way You Think About Change Problems"},"content":{"rendered":"

Brian Galvin is the Director of Academic Programs at Veritas Prep, where he oversees all of the company\u2019s GMAT preparation courses<\/a>.<\/p>\n

If it\u2019s the autumn of an even-numbered year, change is in the air, or at least in the hot air of the politicians seeking election in November. If you\u2019ve clicked off of the Brown-vs.-Whitman or O\u2019Donnell-vs.-sanity ads long enough to view this post, you\u2019re probably looking to change your GMAT score and your MBA candidacy<\/a>. If so, you\u2019re in luck, because if there\u2019s one thing you can be sure of on the GMAT, it\u2019s change. Ratios, mixtures, proportions \u2014 they\u2019re all GMAT problem types that focus on change.<\/p>\n

And if you focus on that change in each problem, the change becomes the key to unlocking the entire problem \u2013 literally change you can believe in and should depend on. And, with a nod to Hillary Clinton, yes, this change post is one you can certainly Xerox if you\u2019d like to. We don\u2019t mind.<\/p>\n

<\/span><\/p>\n

How can an emphasis on change improve your GMAT score?<\/p>\n

Consider the question:<\/p>\n

The average of 5 numbers is 6.8. If one of the numbers is multiplied by a factor of 3, the average of the numbers increases to 9.2. What number is multiplied by 3?<\/p>\n

(A) 1.5
\n(B) 3.0
\n(C) 3.9
\n(D) 4.0
\n(E) 6.0<\/p><\/blockquote>\n

As with any problem, you should start with what you know. You know that, if the average of 5 numbers is 6.8, then the sum of those numbers is 5*6.8 or 34. Similarly for the new total, if the average is 9.2, then the sum of those five numbers is 5*9.2 or 46.<\/p>\n

So we have:<\/p>\n

Old total: 34
\nNew total: 46<\/p>\n

When problems involve a change \u2013 ratio problems in which a certain number is added or subtracted and the ratio changes; mixture problems in which something is added to or subtracted from the solution and the mixture changes, etc. \u2013 the key to solving them is typically the change itself. Almost always, the change is expressed in two ways:<\/p>\n

x is added and the new ratio becomes\u2026
\none of the numbers is multiplied by 3 and the average becomes\u2026<\/p>\n

When you\u2019re given two ways to mathematically express that change, use those two ways to set up an equation \u2013 you can then solve for a variable that links the past to the present (or the present to the proposed future, depending on how the question is asked) and that solution will allow you to fill in the entire puzzle.<\/p>\n

In this case, we know that \u201cmultiplying one number by 3\u2033 also \u201cincreases the sum by 12\u2033 (46 \u2013 32). Since the only number that changes is that number that is multiplied by 3, we know that the multiplying by 3 is the same as adding 12 to that number. So, mathematically, we can say that:<\/p>\n

3x = x + 12
\n2x = 12
\nx = 6<\/p>\n

Therefore, the number in question \u2013 that which is multiplied by 3 and in doing so is also added to 12 \u2013 is 6, and the correct answer is E.<\/p>\n

Use change as your \u201canchor\u201d in problems that emphasize a change in ratios, proportions, or any other elements of a mixture. By expressing the change in two ways, you\u2019ll have an equation that will translate to both the initial and the final mixtures, and therefore will be able to answer any question that the GMAT asks about any part of the relationship. If politicians can use change as their platform to try to get to Washington, you can certainly use change as your springboard to Boston, Palo Alto, Evanston, or the other b-school campus of your choice.<\/p>\n

Read more GMAT advice in our GMAT lesson booklets<\/a> which are now available for individual purchase.\u00a0 Ready to sign up for a GMAT course<\/a>? Enroll through GMAT Club and save up to $180 (use discount code GMATC10)!<\/p>\n

\"Veritas<\/p>\n","protected":false},"excerpt":{"rendered":"

Brian Galvin is the Director of Academic Programs at Veritas Prep, where he oversees all of the company\u2019s GMAT preparation courses. If it\u2019s the autumn of an even-numbered year, change…<\/p>\n","protected":false},"author":101,"featured_media":0,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[],"class_list":["post-4686","post","type-post","status-publish","format-standard","hentry","category-uncategorized","entry"],"aioseo_notices":[],"_links":{"self":[{"href":"https:\/\/gmatclub.com\/blog\/wp-json\/wp\/v2\/posts\/4686","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/gmatclub.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/gmatclub.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/gmatclub.com\/blog\/wp-json\/wp\/v2\/users\/101"}],"replies":[{"embeddable":true,"href":"https:\/\/gmatclub.com\/blog\/wp-json\/wp\/v2\/comments?post=4686"}],"version-history":[{"count":1,"href":"https:\/\/gmatclub.com\/blog\/wp-json\/wp\/v2\/posts\/4686\/revisions"}],"predecessor-version":[{"id":4688,"href":"https:\/\/gmatclub.com\/blog\/wp-json\/wp\/v2\/posts\/4686\/revisions\/4688"}],"wp:attachment":[{"href":"https:\/\/gmatclub.com\/blog\/wp-json\/wp\/v2\/media?parent=4686"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/gmatclub.com\/blog\/wp-json\/wp\/v2\/categories?post=4686"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/gmatclub.com\/blog\/wp-json\/wp\/v2\/tags?post=4686"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}