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100 points for $49 worth of Veritas practice GMATs FREE VERITAS PRACTICE GMAT EXAMS Earn 10 Points Per Post Earn 10 Points Per Thanks Earn 10 Points Per Upvote ## Dollars tagged by: ceilidh.erickson ##### This topic has 3 expert replies and 2 member replies ## Dollars For each customer, a bakery charges p dollars for the first loaf of bread bought by the customer and charges q dollars for each additional loaf of bought by the customer. What is the value of p? 1) A customer who buys 2 loaves is charged 10 percent less per loaf than a customer who buys a single loaf. 2) A customer who buys 6 loaves of bread is charged 10 dollars. Last edited by Sak32 on Sun Jan 05, 2014 1:47 am; edited 2 times in total ### GMAT/MBA Expert GMAT Instructor Joined 07 Jan 2013 Posted: 417 messages Followed by: 93 members Upvotes: 132 GMAT Score: 750 Just for clarity -- are you submitting this question because you've created it and want to see others try it? Or do you have a question? If it's the first -- feel free to ignore my post. If it's the second -- can you give us an idea of how you tried approaching this one ... or where your struggle was? Thanks! -Brian _________________ _________________ Brian Lange Instructor, Manhattan GMAT Expert Contributor to Beat The GMAT Merci, Danke, Grazie, Gracias -- Whichever way you say it, if you found my post helpful, please click on the 'thank' icon in the top right corner of this post. And I encourage you to click on 'follow' to track all my posts -- all the cool kids are doing it! Free Manhattan Prep online events - The first class of every online Manhattan Prep course is free. Classes start every week. Senior | Next Rank: 100 Posts Joined 14 Oct 2013 Posted: 30 messages No I didn't create it. I know what the answer is its just I had difficulty with the first statement. So if you could provide me with explanations that would be helpful. Thanks. ### GMAT/MBA Expert GMAT Instructor Joined 04 Dec 2012 Posted: 2047 messages Followed by: 238 members Upvotes: 1443 In this question, we have two unknowns: p and q. The golden rule for solving for 2 variables is that we need 2 equations (although there are some exceptions. See here: http://www.beatthegmat.com/to-find-the-ratio-of-adults-to-children-t273004.html#706713 ) (1) A customer who buys 2 loaves is charged 10 percent less per loaf than a customer who buys a single loaf. If we were to set this up algebraically, we'd want to find the average of 2 loaves, and compare it to a single loaf: (p + q)/2 = 0.9p Here, we have one equation with two variables. We can quickly test values to see if this works for multiple scenarios. We weren't given any integer constraints (they don't have to be WHOLE dollar amounts), so we can test anything that fits. If p =$1, then q would equal $0.80 If p =$100, then q would equal $80 Ridiculous for prices of bread, obviously! But the point is - one equation was not enough for us to solve. Insufficient. 2) A customer who buys 6 loaves of bread is charged 10 dollars. Again, set this up algebraically: p + 5q = 10 We can easily see that there are multiple possibilities that would add up to 10: p=5 and q=1, p=2.50 and q=1.50, etc. Insufficient. 1&2 If we put the statements together, we have two equations with two variables. We can solve for q in the first equation: (p + q)/2 = 0.9p p + q = 1.8p q = 0.8p Then we can easily plug it into the second equation and solve. Since it's DS - don't actually do the work! You can see that you'll get a value for p, but you don't have to actually figure out what it is. _________________ Ceilidh Erickson Manhattan Prep GMAT & GRE instructor EdM in Mind, Brain, and Education Harvard Graduate School of Education Manhattan Prep instructors all have 99th+ percentile scores and expert teaching experience. Sign up for a FREE TRIAL, and learn why we have the highest ratings in the GMAT industry! Free Manhattan Prep online events - The first class of every online Manhattan Prep course is free. Classes start every week. ### GMAT/MBA Expert GMAT Instructor Joined 04 Dec 2012 Posted: 2047 messages Followed by: 238 members Upvotes: 1443 Brian brings up a good point here, though: please don't just post a problem without commentary. Let us know why you found it confusing, or what kind of help you want. Please also post your sources, so other people can tell where you got the question. Thanks! _________________ Ceilidh Erickson Manhattan Prep GMAT & GRE instructor EdM in Mind, Brain, and Education Harvard Graduate School of Education Manhattan Prep instructors all have 99th+ percentile scores and expert teaching experience. Sign up for a FREE TRIAL, and learn why we have the highest ratings in the GMAT industry! Free Manhattan Prep online events - The first class of every online Manhattan Prep course is free. Classes start every week. Master | Next Rank: 500 Posts Joined 25 Jul 2011 Posted: 468 messages Followed by: 4 members Upvotes: 29 from 1&2 let the price of first loaf for$5 for two loves @ 10% less be $9 means the second loaf for$4, as of now we dont know the values but ratios
now 5x(1)+4x(5)=10, x = 2/5
price of first loaf = 5(2/5) = 2
price of another 5 loves 4 x 2/5 x 5 =8

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