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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 ## Help Explain. ##### This topic has 2 expert replies and 3 member replies ## Help Explain. What is the least positive integer that is divisible by each of the integers 1 through 7, inclusive? A. 420 B. 840 c. 1260 D. 2520 E. 5040 Please break this down. I feel slow attempting this kind of problem Senior | Next Rank: 100 Posts Joined 28 May 2015 Posted: 62 messages Upvotes: 5 Hello, This is how I could approach, I'll let the experts confirm if this approach is right.. The first thing I noticed is that Option B through E are all multiples of option A. So, if option A is divisible by all integers 1 through 7, that should be the least positive integer divisible by each of the integers 1 through 7 I did a quick check if it is divisible and it is. So, I'll go with Option A Thanks Bullzi Master | Next Rank: 500 Posts Joined 07 Jun 2014 Posted: 126 messages Upvotes: 3 This qus is basically asking LCM of 1,2,3,4,5,6,7.Which is 420. So I think ans is A Pl let us know the OA. Sandip. ### GMAT/MBA Expert Elite Legendary Member Joined 23 Jun 2013 Posted: 10197 messages Followed by: 496 members Upvotes: 2867 GMAT Score: 800 Hi oquiella, This is a great question to TEST THE ANSWERS on, but you have to pay careful attention to what is asked for: we're asked for the LOWEST integer that is divisible by all of those integers. As such, you should NOT start with Answer B or D - you should start with Answer A. If "A" is not correct, then you TEST B, and so on. There is a Number Property rule that you can use to help you to avoid some of the 'excess math.' Any number that is divisible by 6 is ALSO divisible by 2 and 3 So, how long would it take you to determine if 420 is divisible by 7, 5, 4 and 6 (or 3 and 2)? Final Answer: A GMAT assassins aren't born, they're made, Rich _________________ Contact Rich at Rich.C@empowergmat.com Master | Next Rank: 500 Posts Joined 12 May 2015 Posted: 164 messages Upvotes: 3 Rich.C@EMPOWERgmat.com wrote: Hi oquiella, This is a great question to TEST THE ANSWERS on, but you have to pay careful attention to what is asked for: we're asked for the LOWEST integer that is divisible by all of those integers. As such, you should NOT start with Answer B or D - you should start with Answer A. If "A" is not correct, then you TEST B, and so on. There is a Number Property rule that you can use to help you to avoid some of the 'excess math.' Any number that is divisible by 6 is ALSO divisible by 2 and 3 So, how long would it take you to determine if 420 is divisible by 7, 5, 4 and 6 (or 3 and 2)? Final Answer: A GMAT assassins aren't born, they're made, Rich Hi there Im a little confused here...."we're asked for the LOWEST integer that is divisible by all of those integers. As such, you should NOT start with Answer B or D - you should start with Answer A." Why not start with B or D. D is quite large and B is only a little smaller. Can you further explain why you eliminated those first? ### GMAT/MBA Expert Elite Legendary Member Joined 23 Jun 2013 Posted: 10197 messages Followed by: 496 members Upvotes: 2867 GMAT Score: 800 Hi oquiella, I didn't eliminate Answers B and D; I chose not to start with those answers because the prompt asked for the LEAST positive integer that is divisible by 1 through 7, inclusive. If you start by TESTing Answer B and you find that it's divisible by 1 through 7 (which it IS), you won't know if it's actually the smallest integer or not UNTIL you TEST Answer A. That would be a LOT of excessive work if it turns out that Answer A is the correct answer. GMAT assassins aren't born, they're made, Rich _________________ Contact Rich at Rich.C@empowergmat.com • Free Practice Test & Review How would you score if you took the GMAT Available with Beat the GMAT members only code • 1 Hour Free BEAT THE GMAT EXCLUSIVE Available with Beat the GMAT members only code • Award-winning private GMAT tutoring Register now and save up to$200

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