{"id":21555,"date":"2013-11-09T09:00:07","date_gmt":"2013-11-09T16:00:07","guid":{"rendered":"https:\/\/gmatclub.com\/blog\/2013\/11\/gmat-question-of-the-week-data-sufficiency-and-averages-the-explanation\/"},"modified":"2013-11-09T09:00:07","modified_gmt":"2013-11-09T16:00:07","slug":"gmat-question-of-the-week-data-sufficiency-and-averages-the-explanation","status":"publish","type":"post","link":"https:\/\/gmatclub.com\/blog\/gmat-question-of-the-week-data-sufficiency-and-averages-the-explanation\/","title":{"rendered":"GMAT Question of the Week: Data Sufficiency and Averages \u2013 The Explanation"},"content":{"rendered":"
\n\t\t\"GMAT<\/a>\n\t\t<\/div>\n

\n\t\t\"hiAverage\"<\/a><\/p>\n

If you haven't already, visit our Data Sufficiency practice problem<\/a> and give it a try on your own before reading the explanation.<\/p>\n

To get this question correct, you must combine your knowledge of fundamental math concepts with use of the Kaplan Method and strategies for approaching Data Sufficiency. Here\u2019s a breakdown:<\/p>\n

The average formula is Average <\/i>= Sum of the terms \/ Number of terms<\/em><\/strong>.<\/p>\n

The average of m<\/i> and n<\/i> is (m + n) \/ 2 \u00a0. The question stem says \u201cIs \u00a0(m + n) \/ 2\u00a0\u00a0< 50 ?\u201d<\/p>\n

Remember, with a Yes\/No Data Sufficiency<\/b> question, you are looking at the statements and trying to determine whether they provide a consistent<\/i><\/b> YES or NO answer to this question. A consistent answer of yes OR no is sufficient. An inconsistent answer (yes and<\/em> no) is insufficient.<\/p>\n

Statement (1): Sufficient.<\/b> This statement says that (3m + 3n) \/ 2 = 90.<\/p>\n

Pull the 3 out of the numerator to get 3(m + n) \/ 2 = 90,<\/p>\n

Multiply both sides by 2 to get 3(m + n<\/i>) = 180,<\/p>\n

Then divide both sides by 3 to get m + n<\/i> = 60.<\/p>\n

So, the average of m<\/i> and n<\/i> is \u00a0= \u00a0= 30. The average of m<\/i> and n<\/i> is definitely less than 50, and the answer to the question in the stem is always \u201cyes.\u201d Statement (1) is sufficient, so you can eliminate (B), (C), and (E).<\/p>\n

Statement (2): Insufficient.<\/b> This does not allow us to determine the average of m and n, because it does not give us the values or the right relationship between m and n. Eliminate (D).<\/p>\n

Answer choice (A) is correct.<\/p>\n

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

If you haven’t already, visit our Data Sufficiency practice problem and give it a try on your own before reading the explanation. To get this question correct, you must combine…<\/p>\n","protected":false},"author":120,"featured_media":0,"comment_status":"closed","ping_status":"1","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[9,558,243,940],"tags":[],"class_list":["post-21555","post","type-post","status-publish","format-standard","hentry","category-gmat","category-kaplan-blog","category-blog","category-gmat-prep-gmat","entry"],"aioseo_notices":[],"_links":{"self":[{"href":"https:\/\/gmatclub.com\/blog\/wp-json\/wp\/v2\/posts\/21555","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\/120"}],"replies":[{"embeddable":true,"href":"https:\/\/gmatclub.com\/blog\/wp-json\/wp\/v2\/comments?post=21555"}],"version-history":[{"count":0,"href":"https:\/\/gmatclub.com\/blog\/wp-json\/wp\/v2\/posts\/21555\/revisions"}],"wp:attachment":[{"href":"https:\/\/gmatclub.com\/blog\/wp-json\/wp\/v2\/media?parent=21555"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/gmatclub.com\/blog\/wp-json\/wp\/v2\/categories?post=21555"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/gmatclub.com\/blog\/wp-json\/wp\/v2\/tags?post=21555"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}