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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 ## If A, then B. If B, then C.... tagged by: ##### This topic has 9 member replies ## If A, then B. If B, then C.... If A, then B. If B, then C. If C, then D. If all of the statements above are true, which of the following must also be true? A. If D, then A B. If not B, then not C C. If not D, then not A D. If D, then E E. If not A, then not D Master | Next Rank: 500 Posts Joined 19 Mar 2009 Posted: 154 messages Followed by: 1 members Upvotes: 5 figs wrote: If A, then B. If B, then C. If C, then D. If all of the statements above are true, which of the following must also be true? A. If D, then A B. If not B, then not C C. If not D, then not A D. If D, then E E. If not A, then not D I would like to think of all the three statements independent and represent below: A->B B->C C->D A) It cannot be true. C) It cannot be true. D) Out of scope. E) It cannot be true. B) If not B then not C is true. The answer is B. Legendary Member Joined 04 Nov 2008 Posted: 575 messages Followed by: 4 members Upvotes: 18 Test Date: 09-Jul-2009 GMAT Score: 710 IMO B Legendary Member Joined 27 Aug 2008 Posted: 1035 messages Followed by: 1 members Upvotes: 104 would go for C If A, then B. If B, then C. If C, then D =>if A then D =>if not D, then not A Master | Next Rank: 500 Posts Joined 13 Apr 2009 Posted: 154 messages Upvotes: 3 figs wrote: If A, then B. If B, then C. If C, then D. If all of the statements above are true, which of the following must also be true? A. If D, then A B. If not B, then not C C. If not D, then not A D. If D, then E E. If not A, then not D My answer: None of the above. B sounds like a plausible choice at first, but not B doesn't necessarily imply not C. If it rains tomorrow, I will have hot chocolate. If it doesn't rain tomorrow, I will also have hot chocolate (or I may not). Master | Next Rank: 500 Posts Joined 26 Feb 2009 Posted: 113 messages Test Date: June 10, 2009 Target GMAT Score: 700+ GMAT Score: 650 figs wrote: If A, then B. If B, then C. If C, then D. If all of the statements above are true, which of the following must also be true? A. If D, then A B. If not B, then not C C. If not D, then not A D. If D, then E E. If not A, then not D Figs can you post the OA pls? Master | Next Rank: 500 Posts Joined 19 Mar 2009 Posted: 154 messages Followed by: 1 members Upvotes: 5 KICKGMATASS123 wrote: figs wrote: If A, then B. If B, then C. If C, then D. If all of the statements above are true, which of the following must also be true? A. If D, then A B. If not B, then not C C. If not D, then not A D. If D, then E E. If not A, then not D Figs can you post the OA pls? The OA is C This is a logic problem and we shouldn't be expecting this as part of the GMAT. I am going to show how we can get it from truth table. (-> is then) From the given information, we can conclude that A->D is true. I will construct the truth table using http://en.wikipedia.org/wiki/Truth_table#Logical_implication T= TRUE F=FALSE Please look at the file attached. A->D and ~D->~A have the same truth table and hence is the right answer. Attachments This post contains an attachment. You must be logged in to download/view this file. Please login or register as a user. Master | Next Rank: 500 Posts Joined 24 May 2009 Posted: 385 messages Upvotes: 11 Test Date: 2011. Practicing now Target GMAT Score: 800 GMAT Score: 740 Another (slightly simplified) way of seeing this is as follows: A implies B B implies C C implies D all together imply that A implies D. By the contrapositive (not converse!), we have that not D implies not A. Generally, for ALL statements, if A implies B, then "not B" implies " not A". For example, if you're a human, you have a brain. If you don't have a brain, you're not a human. _________________ Have you wondered how you could have found such a treasure? -T Master | Next Rank: 500 Posts Joined 22 Aug 2015 Posted: 200 messages Cannot decide between A and B. Can anyone brake down these two choices for me please Junior | Next Rank: 30 Posts Joined 20 Apr 2017 Posted: 21 messages Hello would you explain more? I thought in this way: a: staying hungry b: getting sick c: leaving work d: no money! then if A doesn't happen, D will not happen but D can happen independently am I wrong?? • Free Veritas GMAT Class Experience Lesson 1 Live Free 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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