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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 algebra- inequalities tagged by: Brent@GMATPrepNow This topic has 1 expert reply and 1 member reply algebra- inequalities Is y a negative number? 1) y +2 is positive 2) y^2 > 10 please explain the second part (inequality) Legendary Member Joined 14 Aug 2012 Posted: 1556 messages Followed by: 34 members Upvotes: 448 Target GMAT Score: 750 GMAT Score: 650 To find: y is negative? Statement 1: y+2 positive. Y = -1 , y+2 = -1+2 = 1 YES Y = 0 , y+2 = 0+2 = 2 NO INSUFFICIENT Statement 2: y^2 > 10 y = -4 ==> y^2 = 16 y = +4 ==> y^2 = 16 INSUFFICIENT Combining... for y+2 to be positive.. the negative value of y >= -1.9 for y^2 > 10.. we need y <-3._ oy y>3._ hence, Y is Positive SUFFICIENT {C} _________________ R A H U L GMAT/MBA Expert GMAT Instructor Joined 08 Dec 2008 Posted: 12827 messages Followed by: 1247 members Upvotes: 5254 GMAT Score: 770 pritam.ryders wrote: Is y a negative number? 1) y + 2 is positive 2) yÂ² > 10 Target question: Is y negative? Statement 1: y + 2 is positive In other words, y + 2 > 0 Subtract 2 from both sides to get y > -2 From this information, can we determine whether or not y is negative? No. Consider these two conflicting cases: Case a: y = -1, in which case y IS negative Case b: y = 1, in which case y is NOT negative Since we cannot answer the target question with certainty, statement 1 is NOT SUFFICIENT Statement 2: yÂ² > 10 There are two possible sets of y-values that satisfy this inequality Case a: y > âˆš10, in which case y is NOT negative Case b: y < -âˆš10, in which case y IS negative Since we cannot answer the target question with certainty, statement 2 is NOT SUFFICIENT Statements 1 and 2 combined Statement 2 presents us with two possible cases: Case a: y > âˆš10 Case b: y < -âˆš10 Statement 1 tells us that y > -2. This eliminates case b, since y cannot simultaneously be greater than -2 AND less than -âˆš10 (â‰ˆ3.2). This means that it MUST be the case that y > âˆš10, which means y is definitely NOT negative. Since we can answer the target question with certainty, the combined statements are SUFFICIENT Answer = C Cheers, Brent _________________ Brent Hanneson â€“ Creator of GMATPrepNow.com Use our video course along with Sign up for our free Question of the Day emails And check out all of our free resources GMAT Prep Now's comprehensive video course can be used in conjunction with Beat The GMATâ€™s FREE 60-Day Study Guide and reach your target score in 2 months! • 5-Day Free Trial 5-day free, full-access trial TTP Quant Available with Beat the GMAT members only code • Get 300+ Practice Questions 25 Video lessons and 6 Webinars for FREE Available with Beat the GMAT members only code • Free Veritas GMAT Class Experience Lesson 1 Live Free Available with Beat the GMAT members only code • Free Practice Test & Review How would you score if you took the GMAT Available with Beat the GMAT members only code • Magoosh Study with Magoosh GMAT prep Available with Beat the GMAT members only code • 5 Day FREE Trial Study Smarter, Not Harder Available with Beat the GMAT members only code • Free Trial & Practice Exam BEAT THE GMAT EXCLUSIVE Available with Beat the GMAT members only code • 1 Hour Free BEAT THE GMAT EXCLUSIVE Available with Beat the GMAT members only code • FREE GMAT Exam Know how you'd score today for$0

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