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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 ## A building has 48 one- and two-bedroom apartments to rent, ##### This topic has 1 expert reply and 0 member replies ### Top Member ## A building has 48 one- and two-bedroom apartments to rent, ## Timer 00:00 ## Your Answer A B C D E ## Global Stats Difficult A building has 48 one- and two-bedroom apartments to rent, some with balconies and others without. If one of these apartments is to be selected at random, is the probability greater than 1/2 that the apartment has two bedrooms and a balcony? (1) Of the apartments, 40 have two bedrooms. (2) Of the apartments, 30 have a balcony. OA E Source: EMPOWERgmat ### GMAT/MBA Expert GMAT Instructor Joined 22 Aug 2016 Posted: 1898 messages Followed by: 30 members Upvotes: 470 Top Reply BTGmoderatorDC wrote: A building has 48 one- and two-bedroom apartments to rent, some with balconies and others without. If one of these apartments is to be selected at random, is the probability greater than 1/2 that the apartment has two bedrooms and a balcony? (1) Of the apartments, 40 have two bedrooms. (2) Of the apartments, 30 have a balcony. OA E Source: EMPOWERgmat Given: A building has 48 one- and two-bedroom apartments to rent, some with balconies and others without. Question: If one of these apartments is to be selected at random, is the probability greater than 1/2 that the apartment has two bedrooms and a balcony? Let's take each statement one by one. (1) Of the apartments, 40 have two bedrooms. Case 1: Say all the 40 two-bedroom apartments have a balcony, then the probability that the apartment has two bedrooms and a balcony = 40/48 = 5/6 > 1/2 (greater than 1/2 ). The answer is Yes. Case 2: Say none of the 40 two-bedroom apartments have a balcony, then the probability that the apartment has two bedrooms and a balcony = 0/48 = 0 < 1/2 (less than 1/2 ). The answer is No. Insufficient. (2) Of the apartments, 30 have a balcony. Case 1: Say there are 30 two-bedroom apartments and each has a balcony, then the probability that the apartment has two bedrooms and a balcony = 30/48 = 5/8 > 1/2 (greater than 1/2 ). The answer is Yes. Case 2: Say there are 30 one-bedroom apartments and each has a balcony, then the probability that the apartment has two bedrooms and a balcony = 0/48 = 0 < 1/2 (less than 1/2 ). The answer is No. Insufficient. (1) and (2) together Case 1: Say 30 of the 40 two-bedroom apartments have a balcony, then the probability that the apartment has two bedrooms and a balcony = 30/48 = 5/8 > 1/2 (greater than 1/2 ). The answer is Yes. Case 2: Since there are 40 two-bedroom apartments, thus, there are 48 - 40 = 8 one-bedroom apartments. Say all the 8 one-bedroom apartments have a balcony, thus, only 30 - 8 = 22 two-bedroom apartments have a balcony. Thus, the probability that the apartment has two bedrooms and a balcony = 22/48 = 11/24 < 1/2 (less than 1/2 ). The answer is No. Insufficient. The correct answer: E Hope this helps! -Jay _________________ Manhattan Review GMAT Prep Locations: New York | New Delhi | Seoul | Cairo | and many more... Schedule your free consultation with an experienced GMAT Prep Advisor! Click here. • Free Practice Test & Review How would you score if you took the GMAT Available with Beat the GMAT members only code • Free Trial & Practice Exam BEAT THE GMAT EXCLUSIVE Available with Beat the GMAT members only code • 5 Day FREE Trial Study Smarter, Not Harder 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 5-day free, full-access trial TTP Quant Available with Beat the GMAT members only code • Award-winning private GMAT tutoring Register now and save up to$200

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