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Of the 60 animals on a certain farm, 2/3 are either cows or

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Veritas Prep GMAT Instructor
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Of the 60 animals on a certain farm, 2/3 are either cows or [#permalink]

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11 Jul 2014, 18:20
Expert's post
rbaudoin10 wrote:
What about the 20 extra animals ? Why can't they be cows or pigs as well within that set ? Nothing is mentioned about these 20 animals. We just know that 40 animals are either pigs or cows. Does anyone get my point ?

Having 13 pigs, 27 cows, and 20 other animals is a possiblity.

Having 14 pigs, 30 cows and 16 other animals is another possibility.

Following that logic, E is the right answer.

To add to what Bunuel said:

It is similar to: Of the 100 people in a room, 40 are men.
What does this mean to you? It means that 60 are not men, right?

Similarly, Of the 60 animals on a certain farm, 40 are either pigs or cows.
This means that rest of the 20 are neither pigs nor cows!

When you are given concrete numbers, it implies that the group has been considered. If only some people were considered, you would have been given "Of the 100 people in a room, at least 40 are men."
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Get started with Veritas Prep GMAT On Demand for $199 Veritas Prep Reviews Senior Manager Joined: 15 Aug 2013 Posts: 328 Followers: 0 Kudos [?]: 38 [0], given: 23 Re: Of the 60 animals on a certain farm, 2/3 are either cows or [#permalink] Show Tags 30 Aug 2014, 11:31 Bunuel wrote: shrivastavarohit wrote: Guys I don't know how long this post has been here however I thought I would add my 2 cents and see if what I feel should be the answer. Question says something either a cow or a pig form the ratio of 2/3. I don't feel 60 number is of much significance since this is DS. 1) says the mix is 1 to 2. So if by simple math I find what's remaining out of 2/3 the ratio comes out to be 1/3. At this moment for me the information in the statement 1 becomes helpful. Since 2wice of 1/3 is 2/3 and we know that 2wice as many cows hence this information is sufficient. Posted from my mobile device Of the 60 animals on a certain farm, 2/3 are either pigs or cows. How many of the animals are cows? (1) The farm has more than twice as many cows as it has pigs --> so we have is $$c>2p$$ and not $$c=2p$$ --> as $$c+p=40$$ (p=40-c and c=40-p) --> $$40-p>2p$$, $$13.3>p$$, $$p_{max}=13$$ and $$c_{min}=27$$. Many combinations are possible: (27,13), (28, 12), ... Not sufficient. (2) $$p>12$$. Not sufficient (1)+(2) $$p>12$$ but $$p_{max}=13$$, hence $$p=13$$ --> $$c=27$$. Sufficient. Answer: C. One more thing: if the ratio indeed were $$c=2p$$, then the question would be flawed as solving $$c=2p$$ and $$c+p=40$$ gives $$p=13.3$$, but # of pigs can not be a fraction it MUST be an integer. Hi Bunuel, Two questions: -How do you know that Cmin is 27? I can se how Pmax is 13, but I don't really see how that translates onto Cmin? -If I were to add Stm 1 and Stm 2, I get c-p>12. That, algebraically, doesn't help solve the problem Am I correct? Math Expert Joined: 02 Sep 2009 Posts: 33552 Followers: 5945 Kudos [?]: 73799 [1] , given: 9903 Re: Of the 60 animals on a certain farm, 2/3 are either cows or [#permalink] Show Tags 01 Sep 2014, 00:48 1 This post received KUDOS Expert's post 1 This post was BOOKMARKED russ9 wrote: Bunuel wrote: shrivastavarohit wrote: Guys I don't know how long this post has been here however I thought I would add my 2 cents and see if what I feel should be the answer. Question says something either a cow or a pig form the ratio of 2/3. I don't feel 60 number is of much significance since this is DS. 1) says the mix is 1 to 2. So if by simple math I find what's remaining out of 2/3 the ratio comes out to be 1/3. At this moment for me the information in the statement 1 becomes helpful. Since 2wice of 1/3 is 2/3 and we know that 2wice as many cows hence this information is sufficient. Posted from my mobile device Of the 60 animals on a certain farm, 2/3 are either pigs or cows. How many of the animals are cows? (1) The farm has more than twice as many cows as it has pigs --> so we have is $$c>2p$$ and not $$c=2p$$ --> as $$c+p=40$$ (p=40-c and c=40-p) --> $$40-p>2p$$, $$13.3>p$$, $$p_{max}=13$$ and $$c_{min}=27$$. Many combinations are possible: (27,13), (28, 12), ... Not sufficient. (2) $$p>12$$. Not sufficient (1)+(2) $$p>12$$ but $$p_{max}=13$$, hence $$p=13$$ --> $$c=27$$. Sufficient. Answer: C. One more thing: if the ratio indeed were $$c=2p$$, then the question would be flawed as solving $$c=2p$$ and $$c+p=40$$ gives $$p=13.3$$, but # of pigs can not be a fraction it MUST be an integer. Hi Bunuel, Two questions: -How do you know that Cmin is 27? I can se how Pmax is 13, but I don't really see how that translates onto Cmin? -If I were to add Stm 1 and Stm 2, I get c-p>12. That, algebraically, doesn't help solve the problem Am I correct? There are total of 40 pigs and cows. We know that there are at most 13 pigs (13 or less). Thus there are at least 27 cows. Or: p + c = 40 and p <= 13 --> (40 - c) <= 13 --> c >= 27. Hope it's clear. _________________ Intern Joined: 11 Sep 2014 Posts: 8 Followers: 0 Kudos [?]: 2 [1] , given: 5 Re: Of the 60 animals on a certain farm, 2/3 are either cows or [#permalink] Show Tags 29 Sep 2014, 07:58 1 This post received KUDOS Bunuel wrote: ngoctraiden1905 wrote: From your ans I think the stem means 2/3 of 60 animals are both pigs and cows, not either pigs or cows. I think there is some problem with stem here? How it's possible for an animal to be BOTH a pig and a cow? 2/3 of 60 animals are either pigs or cows. So there are total of 40 cows and pigs. Yansta8's solution is correct. C it is. Maybe they are half cow, half bear, half pig.... Cowbearpig _________________ What we think, we become Intern Joined: 03 Jul 2014 Posts: 17 Followers: 0 Kudos [?]: 1 [0], given: 19 Re: Of the 60 animals on a certain farm, 2/3 are either cows or [#permalink] Show Tags 25 Nov 2014, 04:17 I guess we cannot solve it using Matrix method as , Both cannot be Cow and Pig . Is there any alternative method to solve this . Thanks Bunuel wrote: Syed wrote: yangsta8 wrote: Question stem says that 2/3 of 60 are pigs or cows. That means 40 animals are pigs or cows. So all we need to have sufficiency is either number of pigs or number of cows. 1) Farm has more than 2 cows for 1 pig (at least 26.6 animals of the 40 are cows). This just tells us that the farm has at least 27 pigs and that the max number of cows is 13. For example the farm could have 30 pigs and 10 cows. Not a definitive number. Insufficient. 2) Farm has more than 12 pigs. Again not enough info. Insuff 1+2) Statements together tell us: 12 < number of pigs is <=13 Which means number pigs = 13 Number of cows = 27. ANSWER = C. I do agree with 'yangsta8' that the answer is 'C' but (if I am NOT wrong), Stmnt#1 says the number of Cows are more than twice than the pigs. Thus, the cows could be 27 and Pigs could be 13; and For example, the farm could have 30 cows and 10 pigs. ------------------------------- Hi Bunuel and Yangsta8 - Please correct me if I am wrong (which is very much possible)! c+p=40 (1) c>2p --> min # of cows is 27 and max # pigs is 13, so there can be any combination not violating this and totaling 40. Not sufficient (2) p>12 Not sufficient (1)+(2) p>12 but max of p is 13, hence p=13 --> c=27 You are right there can be 27 cows (min) and 13 pigs (max) or 30 cows and 10 pigs. Think there was simple typo from yangsta8. Director Joined: 07 Aug 2011 Posts: 582 Concentration: International Business, Technology GMAT 1: 630 Q49 V27 Followers: 3 Kudos [?]: 323 [0], given: 75 Re: Of the 60 animals on a certain farm, 2/3 are either cows or [#permalink] Show Tags 14 Mar 2015, 07:34 Bunuel wrote: ngoctraiden1905 wrote: From your ans I think the stem means 2/3 of 60 animals are both pigs and cows, not either pigs or cows. I think there is some problem with stem here? How it's possible for an animal to be BOTH a pig and a cow? 2/3 of 60 animals are either pigs or cows. So there are total of 40 cows and pigs. Yansta8's solution is correct. C it is. Sorry Bunuel/Experts, i could not get why is A not sufficient . statement A : C > 2P then must be C>P for all positive integer values of C and P . now we know Cows are more in number , so from question stem 2/3 are cows and hence 1/3 will be pigs . where am i missing( i know i am falling in a intended trap of this question ) ? _________________ Thanks, Lucky _______________________________________________________ Kindly press the to appreciate my post !! Math Expert Joined: 02 Sep 2009 Posts: 33552 Followers: 5945 Kudos [?]: 73799 [0], given: 9903 Re: Of the 60 animals on a certain farm, 2/3 are either cows or [#permalink] Show Tags 14 Mar 2015, 07:48 Expert's post Lucky2783 wrote: Bunuel wrote: ngoctraiden1905 wrote: From your ans I think the stem means 2/3 of 60 animals are both pigs and cows, not either pigs or cows. I think there is some problem with stem here? How it's possible for an animal to be BOTH a pig and a cow? 2/3 of 60 animals are either pigs or cows. So there are total of 40 cows and pigs. Yansta8's solution is correct. C it is. Sorry Bunuel/Experts, i could not get why is A not sufficient . statement A : C > 2P then must be C>P for all positive integer values of C and P . now we know Cows are more in number , so from question stem 2/3 are cows and hence 1/3 will be pigs . where am i missing( i know i am falling in a intended trap of this question ) ? Your doubt is answered on previous pages. Of the 60 animals on a certain farm, 2/3 are either pigs or cows. Hence 40 animals are either pigs or cows, meaning that out of 40 animals some are pigs and the rest are cows: p+c=40. (1) The farm has more than twice as many cows as pigs --> c > 2p --> min # of cows is 27 and max # pigs is 13, so there can be any combination not violating this and totaling 40. Not sufficient _________________ Verbal Forum Moderator Joined: 02 Aug 2009 Posts: 3947 Followers: 232 Kudos [?]: 2308 [0], given: 97 Re: Of the 60 animals on a certain farm, 2/3 are either cows or [#permalink] Show Tags 14 Mar 2015, 07:51 Expert's post Lucky2783 wrote: Sorry Bunuel/Experts, i could not get why is A not sufficient . statement A : C > 2P then must be C>P for all positive integer values of C and P . now we know Cows are more in number , so from question stem 2/3 are cows and hence 1/3 will be pigs . where am i missing( i know i am falling in a intended trap of this question ) ? hi Lucky2783, what are you are missing is the meaning of question stem... it says 2/3 are either pigs or cows.... this means that out of 60, 2/3rd that is 40 are either pigs or cows and rest can be any other animal other than this two... it does not say that 2/3 are one of the two and 1/3 remaining are the other of the two... Of the 60 animals on a certain farm, 2/3 are either pigs or cows. How many of the animals are cows? (1) The farm has more than twice as many cows as pigs (2) The farm has more than 12 pigs _________________ Absolute modulus :http://gmatclub.com/forum/absolute-modulus-a-better-understanding-210849.html#p1622372 Combination of similar and dissimilar things : http://gmatclub.com/forum/topic215915.html Director Joined: 07 Aug 2011 Posts: 582 Concentration: International Business, Technology GMAT 1: 630 Q49 V27 Followers: 3 Kudos [?]: 323 [0], given: 75 Re: Of the 60 animals on a certain farm, 2/3 are either cows or [#permalink] Show Tags 14 Mar 2015, 09:21 chetan2u wrote: Lucky2783 wrote: Sorry Bunuel/Experts, i could not get why is A not sufficient . statement A : C > 2P then must be C>P for all positive integer values of C and P . now we know Cows are more in number , so from question stem 2/3 are cows and hence 1/3 will be pigs . where am i missing( i know i am falling in a intended trap of this question ) ? hi Lucky2783, what are you are missing is the meaning of question stem... it says 2/3 are either pigs or cows.... this means that out of 60, 2/3rd that is 40 are either pigs or cows and rest can be any other animal other than this two... it does not say that 2/3 are one of the two and 1/3 remaining are the other of the two... Of the 60 animals on a certain farm, 2/3 are either pigs or cows. How many of the animals are cows? (1) The farm has more than twice as many cows as pigs (2) The farm has more than 12 pigs ohhh god !! thats a very callous mistake at my end . thanks chetan. _________________ Thanks, Lucky _______________________________________________________ Kindly press the to appreciate my post !! Director Joined: 07 Aug 2011 Posts: 582 Concentration: International Business, Technology GMAT 1: 630 Q49 V27 Followers: 3 Kudos [?]: 323 [0], given: 75 Of the 60 animals on a certain farm, 2/3 are either cows or [#permalink] Show Tags 14 Mar 2015, 09:23 I misinterpreted the question stem . thanks for the clarification Bunuel . Thanks, Lucky. _________________ Thanks, Lucky _______________________________________________________ Kindly press the to appreciate my post !! GMAT Club Legend Joined: 09 Sep 2013 Posts: 10229 Followers: 482 Kudos [?]: 124 [0], given: 0 Re: Of the 60 animals on a certain farm, 2/3 are either cows or [#permalink] Show Tags 21 Mar 2016, 17:47 Hello from the GMAT Club BumpBot! Thanks to another GMAT Club member, I have just discovered this valuable topic, yet it had no discussion for over a year. I am now bumping it up - doing my job. I think you may find it valuable (esp those replies with Kudos). Want to see all other topics I dig out? Follow me (click follow button on profile). You will receive a summary of all topics I bump in your profile area as well as via email. _________________ Intern Joined: 22 Mar 2015 Posts: 28 Followers: 0 Kudos [?]: 3 [0], given: 14 Re: Of the 60 animals on a certain farm, 2/3 are either cows or [#permalink] Show Tags 28 Mar 2016, 10:01 DenisSh wrote: Of the 60 animals on a certain farm, 2/3 are either pigs or cows. How many of the animals are cows? (1) The farm has more than twice as many cows as pigs (2) The farm has more than 12 pigs Hello Bunuel, In this question, I made a tragic mistake of considering No. of cows=40 OR Number of pigs=40. Since its a GMAT Prep question, I can certainly expect such kind of questions to come on GMAT. Can you please suggest me what can I do to avoid such kind of mistakes in future ? Also: 1.) Should I consider every OR to be a plus if it is being presented in an ambiguous way (Such as in this question) ? Thanks Devansh Verbal Forum Moderator Joined: 02 Aug 2009 Posts: 3947 Followers: 232 Kudos [?]: 2308 [0], given: 97 Re: Of the 60 animals on a certain farm, 2/3 are either cows or [#permalink] Show Tags 28 Mar 2016, 10:16 Expert's post Devlikes wrote: DenisSh wrote: Of the 60 animals on a certain farm, 2/3 are either pigs or cows. How many of the animals are cows? (1) The farm has more than twice as many cows as pigs (2) The farm has more than 12 pigs Hello Bunuel, In this question, I made a tragic mistake of considering No. of cows=40 OR Number of pigs=40. Since its a GMAT Prep question, I can certainly expect such kind of questions to come on GMAT. Can you please suggest me what can I do to avoid such kind of mistakes in future ? Also: 1.) Should I consider every OR to be a plus if it is being presented in an ambiguous way (Such as in this question) ? Thanks Devansh Hi, EITHER.. OR .. used in this context would always means the two comdined are 40.. If the Q, means pigs or cows= 40, It would mention somewhere that only one kind of animal is there in farm or .. Of the 60 animals on a certain farm, 2/3 are either only pigs or only cows.. _________________ Absolute modulus :http://gmatclub.com/forum/absolute-modulus-a-better-understanding-210849.html#p1622372 Combination of similar and dissimilar things : http://gmatclub.com/forum/topic215915.html Intern Joined: 27 Feb 2015 Posts: 27 Concentration: General Management, Economics GMAT 1: 540 Q V WE: Engineering (Transportation) Followers: 0 Kudos [?]: 2 [0], given: 26 Re: Of the 60 animals on a certain farm, 2/3 are either cows or [#permalink] Show Tags 29 Mar 2016, 00:25 hello, please help me explain why this Q cannot be interpreted as Given: total = 60 ...either cow or pig is 40 i.e. c=40 or p=40 to find: c=? 1) c>2p if C=40 ; p< 20 so other animal >1 ...eg : if c=40 ; p = 15 ; others =5. so here if get c=40 now if p=40 so c>80 which cannot happen since total is 60 either of c or p has to be 40; so from here we get c=40 , that is what we want SUFFICIENT 2) p>12 clearly not sufficent. so ans should be A thanks . _________________ 1st attempt was mock ; 2nd attempt I will rock. Manager Joined: 03 Dec 2014 Posts: 116 Location: United States Concentration: General Management, Operations GPA: 1.9 WE: Engineering (Energy and Utilities) Followers: 2 Kudos [?]: 27 [0], given: 342 Re: Of the 60 animals on a certain farm, 2/3 are either cows or [#permalink] Show Tags 29 Mar 2016, 03:35 yangsta8 wrote: Question stem says that 2/3 of 60 are pigs or cows. That means 40 animals are pigs or cows. So all we need to have sufficiency is either number of pigs or number of cows. 1) Farm has more than 2 cows for 1 pig (at least 26.6 animals of the 40 are cows). This just tells us that the farm has at least 27 pigs and that the max number of cows is 13. For example the farm could have 30 pigs and 10 cows. Not a definitive number. Insufficient. 2) Farm has more than 12 pigs. Again not enough info. Insuff 1+2) Statements together tell us: 12 < number of pigs is <=13 Which means number pigs = 13 Number of cows = 27. ANSWER = C. does the farm has only cow and pig , no other animal. The question stem does not make it clear? Answer, in my view, should be E Math Expert Joined: 02 Sep 2009 Posts: 33552 Followers: 5945 Kudos [?]: 73799 [1] , given: 9903 Re: Of the 60 animals on a certain farm, 2/3 are either cows or [#permalink] Show Tags 29 Mar 2016, 03:50 1 This post received KUDOS Expert's post robu wrote: yangsta8 wrote: Question stem says that 2/3 of 60 are pigs or cows. That means 40 animals are pigs or cows. So all we need to have sufficiency is either number of pigs or number of cows. 1) Farm has more than 2 cows for 1 pig (at least 26.6 animals of the 40 are cows). This just tells us that the farm has at least 27 pigs and that the max number of cows is 13. For example the farm could have 30 pigs and 10 cows. Not a definitive number. Insufficient. 2) Farm has more than 12 pigs. Again not enough info. Insuff 1+2) Statements together tell us: 12 < number of pigs is <=13 Which means number pigs = 13 Number of cows = 27. ANSWER = C. does the farm has only cow and pig , no other animal. The question stem does not make it clear? Answer, in my view, should be E Please read the whole thread, your doubt is answered couple of times on previous pages. Also, this is GMAT Prep official question, no sense to doubt the answer. _________________ Intern Joined: 22 May 2016 Posts: 1 Followers: 0 Kudos [?]: 0 [0], given: 1 Re: Of the 60 animals on a certain farm, 2/3 are either cows or [#permalink] Show Tags 26 Jun 2016, 02:42 I believe answer should be E. As question demands number of cows among animals, we can form many other combinations from given 1st and 2nd statement. For ex. Pigs = 30, Cows = 10. S1: More than twice as many cows as pigs. 30 > 10*2 S2: Number of pigs more than 12. 30>12 Similarly many other combinations are possible like, (28,12), (32,8) etc. Kindly help. Veritas Prep GMAT Instructor Joined: 16 Oct 2010 Posts: 6681 Location: Pune, India Followers: 1832 Kudos [?]: 11153 [0], given: 219 Re: Of the 60 animals on a certain farm, 2/3 are either cows or [#permalink] Show Tags 26 Jun 2016, 05:41 Expert's post ngoyal2 wrote: I believe answer should be E. As question demands number of cows among animals, we can form many other combinations from given 1st and 2nd statement. For ex. Pigs = 30, Cows = 10. S1: More than twice as many cows as pigs. 30 > 10*2 S2: Number of pigs more than 12. 30>12 Similarly many other combinations are possible like, (28,12), (32,8) etc. Kindly help. S1: The farm has more than twice as many cows as pigs implies Number of cows is more than twice the number of pigs. C > 2P Hence Pigs = 30, Cows = 10 doesn't work. Neither do the other examples you have given. _________________ Karishma Veritas Prep | GMAT Instructor My Blog Get started with Veritas Prep GMAT On Demand for$199

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Re: Of the 60 animals on a certain farm, 2/3 are either cows or   [#permalink] 26 Jun 2016, 05:41

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