by Rich Cohen, Rich.C@empowergmat.com \u00a0www.EMPOWERgmat.com<\/p>\n
This series of emails and PMs focuses on situations that many Test Takers face during their studies. The names of the original posters have been changed to protect their identities.<\/p>\n
The Basics Behind Prime Factorization<\/strong> This question has kept me occupied for the entire day. I am trying to arrive at a general concept here.<\/p>\n \"If a number Z is divisible by X, when would it also be divisible by Y\"?<\/p>\n For Example: the number 108 is divisible by 27 and also divisible by 54. When would a number be divisible by both 27 and 54? What's the general concept hidden behind this problem that GMAT would try to test?<\/p>\n There is something it has got to do with the factors, but I just can't get clarity.<\/p>\n Uter<\/p>\n Hi Uter,<\/p>\n The concept that you've mentioned in this post is ultimately about \"prime factorization\" - by knowing what prime factors divide evenly into a number, you can figure out all of the possible values that can divide evenly into that number.<\/p>\n For example, the number 20 = 2x2x5<\/p>\n This means that the following numbers will divide evenly into 20: This rule tends to come in handy when dealing with really big numbers or when trying to figure out the values at which numbers overlap with one another.<\/p>\n For example, what's the least common multiple of 4 and 6?<\/p>\n 4 = 2x2 Notice how BOTH terms include one \"2\"? In this scenario, you DON'T count that 2 twice \u2013 you count it ONCE.<\/p>\n The LCM of 4 and 6 = 2x2x3 = 12<\/p>\n The Standard Work Formula Question That You Might See on Test Day<\/strong> I know this is a work question, but I got stuck and I\u2019m not sure how best to approach these questions.<\/p>\n If Sally can paint a house in 4 hours, and John can paint the same house in 6 hour, how long will it take for both of them to paint the house together?<\/p>\n A. 2 hours and 24 minutes My workout :<\/p>\n 1\/4 +1\/6 = 5\/12, but I\u2019m stuck after this.<\/p>\n Vernon<\/p>\n Hi Vernon,<\/p>\n This question involves 2 people working on a job together, so it's perfect for the Work Formula:<\/p>\n Work = (AxB)\/(A+B)<\/p>\n A and B represent the amount of time that it takes each person to paint the house:<\/p>\n A = 4 hours Now plug in\u2026<\/p>\n (4x6)\/(4+6) = 24\/10 hours<\/p>\n 2.4 hours = 2 hours 24 minutes<\/p>\n Final Answer: A<\/p>\n Your approach would also get you the correct answer. You\u2019ve calculated the amount of the \u201cjob\u201d that gets done in 1 hour. By \u2018flipping\u2019 that fraction (re: 5\/12 \u2018flips\u2019 to 12\/5), you end up with the total TIME (in hours) it takes to complete the job.<\/p>\n A Competitive Score vs. the School\u2019s Average Score<\/strong> I am aiming to get into top 20-30 B-schools. Will I need a 700 or higher?<\/p>\n Wilhelmina<\/p>\n Hi Wilhelmina,<\/p>\n While most of the Top-20 US Business Schools have an AVERAGE GMAT score of 700+, that's just an average, NOT a requirement. In real basic terms, the higher your GMAT score, the better your \"chances\", but small increases are rarely meaningful (a 670, a 680 and a 690 all \u2018look\u2019 the same to Admissions Committees); a high GMAT score might also help you qualify for a scholarship. Keep in mind that a strong overall application is what it takes to get into B-School and your GMAT score is just one of the parts of the application. If you have a decent GMAT score, but your application \u2018stands out\u2019 in other ways, then you can still get into a Top Business School.<\/p>\n GMAT assassins aren't born, they're made, by Rich Cohen, Rich.C@empowergmat.com \u00a0www.EMPOWERgmat.com This series of emails and PMs focuses on situations that many Test Takers face during their studies. The names of the original posters have been…<\/p>\n","protected":false},"author":156,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[9,1,243,940],"tags":[],"class_list":["post-34063","post","type-post","status-publish","format-standard","hentry","category-gmat","category-uncategorized","category-blog","category-gmat-prep-gmat","entry"],"aioseo_notices":[],"_links":{"self":[{"href":"https:\/\/gmatclub.com\/blog\/wp-json\/wp\/v2\/posts\/34063","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\/156"}],"replies":[{"embeddable":true,"href":"https:\/\/gmatclub.com\/blog\/wp-json\/wp\/v2\/comments?post=34063"}],"version-history":[{"count":2,"href":"https:\/\/gmatclub.com\/blog\/wp-json\/wp\/v2\/posts\/34063\/revisions"}],"predecessor-version":[{"id":34173,"href":"https:\/\/gmatclub.com\/blog\/wp-json\/wp\/v2\/posts\/34063\/revisions\/34173"}],"wp:attachment":[{"href":"https:\/\/gmatclub.com\/blog\/wp-json\/wp\/v2\/media?parent=34063"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/gmatclub.com\/blog\/wp-json\/wp\/v2\/categories?post=34063"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/gmatclub.com\/blog\/wp-json\/wp\/v2\/tags?post=34063"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}
\nHi Rich,<\/p>\n
\n1
\n2
\n4 = 2x2
\n5
\n10 = 2x5
\n20 = 2x2x5<\/p>\n
\n6 = 2x3<\/p>\n
\nDear Rich,<\/p>\n
\nB. 3 hours and 12 minutes
\nC. 3 hours and 44 minutes
\nD. 4 hours and 10 minutes
\nE. 4 hours and 33 minutes<\/p>\n
\nB = 6 hours<\/p>\n
\nRich,<\/p>\n
\nRich<\/p>\n","protected":false},"excerpt":{"rendered":"