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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 ## In the circle above with center O, what is the length of tagged by: BTGmoderatorLU ##### This topic has 1 expert reply and 0 member replies ### Top Member ## In the circle above with center O, what is the length of ## Timer 00:00 ## Your Answer A B C D E ## Global Stats Difficult Source: Veritas Prep In the circle above with center O, what is the length of minor arc BC? $$(1)\ \text{Diameter}\ AC = 24$$ $$(2)\ \text{Chord}\ AB = 12 \sqrt{3}$$ The OA is D. ### GMAT/MBA Expert GMAT Instructor Joined 04 Dec 2012 Posted: 1996 messages Followed by: 237 members Upvotes: 1443 Since we know that minor arc BC is a 60* arc (corresponding to a 30* interior angle), then we know that it makes up 1/6 of the circumference of the circle. If we can find the circumference, we'll know the value of arc BC. (1) diameter AC = 24 Given the diameter, we'll be able to find the value of the circumference. Sufficient. $$(2)\ \text{Chord}\ AB = 12 \sqrt{3}$$ Since AC is a diameter, we can create a 30-60-90 triangle by drawing a line from B to C. Since 30-60-90 triangles always have the same ratio of side lengths, knowing the side length of AB will allow us to infer that the diameter AC is 24. As with statement 1, knowing the diameter is sufficient to tell us the circumference, which is sufficient to tell us the length of arc BC. The answer is D. _________________ 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. • Award-winning private GMAT tutoring Register now and save up to$200

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