if the total price for n copies of a book is $31.5, what is : DS Archive Check GMAT Club Decision Tracker for the Latest School Decision Releases http://gmatclub.com/AppTrack  It is currently 18 Jan 2017, 00:37 GMAT Club Daily Prep Thank you for using the timer - this advanced tool can estimate your performance and suggest more practice questions. We have subscribed you to Daily Prep Questions via email. Customized for You we will pick new questions that match your level based on your Timer History Track Your Progress every week, we’ll send you an estimated GMAT score based on your performance Practice Pays we will pick new questions that match your level based on your Timer History Not interested in getting valuable practice questions and articles delivered to your email? No problem, unsubscribe here. Request Expert Reply Events & Promotions Events & Promotions in June Open Detailed Calendar if the total price for n copies of a book is$31.5, what is

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if the total price for n copies of a book is $31.5, what is [#permalink] Show Tags 14 Jul 2008, 10:00 00:00 Difficulty: (N/A) Question Stats: 0% (00:00) correct 0% (00:00) wrong based on 1 sessions HideShow timer Statistics This topic is locked. If you want to discuss this question please re-post it in the respective forum. if the total price for n copies of a book is$31.5, what is the per copy of the book?
1) if twice as many copies were bought for same total price, the price per copy would be 1,75$2) if 4 fewer copies were bought for the samt total price, the price per copy would be$2.80 greater.
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14 Jul 2008, 10:38
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x=price per copy
n*x=31.5

1. 2n*1.75=31.5
n=9
suff.

2. (n-4)*(x+2.8)=31.5
now it is all about system of equations, you should solve it for n-the number of books bought.
suff.

so D for me

Zaur wrote:
if the total price for n copies of a book is $31.5, what is the per copy of the book? 1) if twice as many copies were bought for same total price, the price per copy would be 1,75$