{"id":7243,"date":"2014-05-29T14:54:44","date_gmt":"2014-05-29T18:54:44","guid":{"rendered":"http:\/\/www.manhattangmat.com\/blog\/?p=7243"},"modified":"2019-09-05T16:03:46","modified_gmt":"2019-09-05T16:03:46","slug":"memorize-this-and-pick-up-2-or-3-gmat-quant-questions-on-the-test","status":"publish","type":"post","link":"https:\/\/www.manhattanprep.com\/gmat\/blog\/memorize-this-and-pick-up-2-or-3-gmat-quant-questions-on-the-test\/","title":{"rendered":"Memorize this and pick up 2 or 3 GMAT quant questions on the test!"},"content":{"rendered":"

\"gmat-quant-tips\"Memorize what? I\u2019m not going to tell you yet. Try this problem from the GMATPrep\u00ae free practice tests first and see whether you can spot the most efficient solution.<\/p>\n

\"Screen<\/p>\n

All right, have you got an answer? How satisfied are you with your solution? If you did get an answer but you don\u2019t feel as though you found an elegant<\/i> solution, take some time to review the problem yourself before you keep reading.<\/p>\n

Step 1: Glance Read Jot<\/i><\/p>\n

Take a quick glance; what have you got? PS. A given equation, xy<\/i> = 1. A seriously ugly-looking equation. Some fairly \u201cnice\u201d numbers in the answers. Hmm, maybe you should work backwards from the answers?<\/p>\n

Jot the given info on the scrap paper.<\/p>\n

Step 2: Reflect Organize<\/i><\/p>\n

Oh, wait. Working backwards isn\u2019t going to work\u2014the answers don\u2019t stand for just a simple variable.<\/p>\n

Okay, what\u2019s plan B? Does anything else jump out from the question stem?<\/p>\n

Hey, those ugly exponents\u2026there is one way in which they\u2019re kind of nice. They\u2019re both one of the three common special products. In general, when you see a special product, try rewriting the problem usually the other<\/i> form of the special product.<\/p>\n

Step 3: Work<\/i><\/p>\n

Here\u2019s the original expression again:<\/p>\n

\"Screen<\/p>\n

Let\u2019s see.<\/p>\n

\"Screen<\/p>\n

Interesting. I like that for two reasons. First of all, a couple of those terms incorporate xy<\/i> and the question stem told me that xy<\/i> = 1, so maybe I\u2019m heading in the right direction. Here\u2019s what I\u2019ve got now:<\/p>\n

\"Screen<\/p>\n

And that takes me to the second reason I like this: the two sets of exponents look awfully similar now, and they gave me a fraction to start. In general, we\u2019re supposed to try to simplify fractions, and we do that by dividing stuff out.<\/p>\n

\"Screen<\/p>\n

How else can I write this to try to divide the similar stuff out? Wait, I\u2019ve got it:<\/p>\n

The numerator:\u00a0\"Screen<\/p>\n

The denominator:\u00a0\"Screen<\/p>\n

They\u2019re almost identical! Both of the\u00a0\"Screenterms cancel out, as do the\u00a0\"Screenterms, leaving me with:<\/p>\n

\"Screen<\/p>\n

I like that a lot better than the crazy thing they started me with. Okay, how do I deal with this last step?<\/p>\n

First, be really careful. Fractions + negative exponents = messy. In order to get rid of the negative exponent, take the reciprocal of the base:<\/p>\n

\"Screen<\/p>\n

Next, dividing by 1\/2 is the same as multiplying by 2:<\/p>\n

\"Screen<\/p>\n

That multiplies to 16, so the correct answer is (D).<\/p>\n

Key Takeaways: Special Products<\/b><\/p>\n

(1) Your math skills have to be solid. If you don\u2019t know how to manipulate exponents or how to simplify fractions, you\u2019re going to get this problem wrong. If you struggle to remember any of the rules, start building and drilling flash cards. If you know the rules but make careless mistakes<\/a> as you work, start writing down every step and pausing to think about where you\u2019re going before you go there. Don\u2019t just run through everything without thinking!<\/p>\n

(2) You need to memorize the special products and<\/i> you also need to know when and how to use them. The test writers LOVE to use special products to create a seemingly impossible question with a very elegant solution. Whenever you spot any form of a special product, write the problem down using both the original form and the other form. If you\u2019re not sure which one will lead to the answer, try the other<\/i> form first, the one they didn\u2019t give you; this is more likely to lead to the correct answer (though not always).<\/p>\n

(3) You may not see your way to the end after just the first step. That\u2019s okay. Look for clues that indicate that you may be on the right track, such as xy<\/i> being part of the other form. If you take a few steps and come up with something totally crazy or ridiculously hard, go back to the beginning and try the other path. Often, though, you\u2019ll find the problem simplifying itself as you get several steps in.<\/p>\n

* GMATPrep\u00ae questions courtesy of the Graduate Management Admissions Council. Usage of this question does not imply endorsement by GMAC.<\/p>\n

\u00a0<\/p>\n

\u00a0<\/p>\n","protected":false},"excerpt":{"rendered":"

Memorize what? I\u2019m not going to tell you yet. Try this problem from the GMATPrep\u00ae free practice tests first and see whether you can spot the most efficient solution. All right, have you got an answer? How satisfied are you with your solution? If you did get an answer but you don\u2019t feel as though […]<\/p>\n","protected":false},"author":6,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[11,8],"tags":[58,61,62,63,233,319,320,322,325,372,393,623],"yst_prominent_words":[],"class_list":["post-7243","post","type-post","status-publish","format-standard","hentry","category-manhattan-gmat-blog-algebra","category-quant-on-gmat","tag-advanced-quant","tag-algebra","tag-algebra-help","tag-algebra-tips","tag-gmat","tag-gmat-quant","tag-gmat-quant-alegbra","tag-gmat-quant-help","tag-gmat-quant-tips","tag-gmat-tips","tag-graduate-management-admissions-test","tag-quant"],"_links":{"self":[{"href":"https:\/\/www.manhattanprep.com\/gmat\/wp-json\/wp\/v2\/posts\/7243","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=7243"}],"version-history":[{"count":1,"href":"https:\/\/www.manhattanprep.com\/gmat\/wp-json\/wp\/v2\/posts\/7243\/revisions"}],"predecessor-version":[{"id":17432,"href":"https:\/\/www.manhattanprep.com\/gmat\/wp-json\/wp\/v2\/posts\/7243\/revisions\/17432"}],"wp:attachment":[{"href":"https:\/\/www.manhattanprep.com\/gmat\/wp-json\/wp\/v2\/media?parent=7243"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.manhattanprep.com\/gmat\/wp-json\/wp\/v2\/categories?post=7243"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.manhattanprep.com\/gmat\/wp-json\/wp\/v2\/tags?post=7243"},{"taxonomy":"yst_prominent_words","embeddable":true,"href":"https:\/\/www.manhattanprep.com\/gmat\/wp-json\/wp\/v2\/yst_prominent_words?post=7243"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}