Author 
Message 
TAGS:

Hide Tags

Manager
Joined: 25 Nov 2011
Posts: 201
Location: India
Concentration: Technology, General Management
GPA: 3.95
WE: Information Technology (Computer Software)

John and Fawn, each drinking at a constant pace, can finish
[#permalink]
Show Tags
17 Feb 2012, 19:53
Question Stats:
57% (01:58) correct 43% (02:12) wrong based on 422 sessions
HideShow timer Statistics
John and Fawn, each drinking at a constant pace, can finish a case of soda together in 12 hours. How fast can John, drinking alone, finish the case? 1) The average time it would take both to finish independently is 30 hours. 2) It would take John 10 more hours to finish the case drinking alone than it would for Fawn to finish the case. This is actually from MGMAT flash cards. Looked interesting and hence I posted after modifying it a bit (I added a new statement).
Official Answer and Stats are available only to registered users. Register/ Login.
_________________
 Aravind Chembeti




Math Expert
Joined: 02 Sep 2009
Posts: 50002

Re: John and Fawn, each drinking at a constant pace, can finish
[#permalink]
Show Tags
17 Feb 2012, 21:55
Chembeti wrote: John and Fawn, each drinking at a constant pace, can finish a case of soda together in 12 hours. How fast can John, drinking alone, finish the case? 1) The average time it would take both to finish independently is 30 hours. 2) It would take John 10 more hours to finish the case drinking alone than it would for Fawn to finish the case. This is actually from MGMAT flash cards. Looked interesting and hence I posted after modifying it a bit (I added a new statement). John and Fawn, each drinking at a constant pace, can finish a case of soda together in 12 hours. How fast can John, drinking alone, finish the case?Given: 1/J + 1/F = 1/12 (1) The average time it would take both to finish independently is 30 hours > J+F=60. Now, since we don't know which one drinks faster then even if we substitute F with 60J (1/J + 1/(60J) = 1/12) we must get two different answers for J and F: J<F and J>F. Not sufficient. (2) It would take John 10 more hours to finish the case drinking alone than it would for Fawn to finish the case > F=J10 > 1/J + 1/(J10) = 1/12 > J=4 (not a valid solution as F in this case is negative) and J=30 ( F=20). Sufficient. Now, technically the answer should be B, as Statement (2) ALONE is sufficient, but statement (1) alone is not sufficient.But even though the formal answer to the question is B, this is not a realistic GMAT question, as: on the GMAT, two data sufficiency statements always provide TRUE information and these statements never contradict each other. In our question, from (2) we have that the average time is (30+20)/2=25 and (1) states that it's 30, so the statements clearly contradict each other. In order it to be a realistic GMAT question (1) should read: The average time it would take John to finish the case drinking alone and Fawn to finish the case drinking alone is 25 hours. In this case for (1) we'll have: 1/J + 1/(50J) = 1/12 > J=30 (so F=20 > J>F) or J=20 (so F=30 > J<F). Statements don't contradict and (1) is still insufficient. Hope it's clear.
_________________
New to the Math Forum? Please read this: Ultimate GMAT Quantitative Megathread  All You Need for Quant  PLEASE READ AND FOLLOW: 12 Rules for Posting!!! Resources: GMAT Math Book  Triangles  Polygons  Coordinate Geometry  Factorials  Circles  Number Theory  Remainders; 8. Overlapping Sets  PDF of Math Book; 10. Remainders  GMAT Prep Software Analysis  SEVEN SAMURAI OF 2012 (BEST DISCUSSIONS)  Tricky questions from previous years.
Collection of Questions: PS: 1. Tough and Tricky questions; 2. Hard questions; 3. Hard questions part 2; 4. Standard deviation; 5. Tough Problem Solving Questions With Solutions; 6. Probability and Combinations Questions With Solutions; 7 Tough and tricky exponents and roots questions; 8 12 Easy Pieces (or not?); 9 Bakers' Dozen; 10 Algebra set. ,11 Mixed Questions, 12 Fresh Meat DS: 1. DS tough questions; 2. DS tough questions part 2; 3. DS tough questions part 3; 4. DS Standard deviation; 5. Inequalities; 6. 700+ GMAT Data Sufficiency Questions With Explanations; 7 Tough and tricky exponents and roots questions; 8 The Discreet Charm of the DS; 9 Devil's Dozen!!!; 10 Number Properties set., 11 New DS set.
What are GMAT Club Tests? Extrahard Quant Tests with Brilliant Analytics




Manager
Status: May The Force Be With Me (DDAY 15 May 2012)
Joined: 06 Jan 2012
Posts: 222
Location: India
Concentration: General Management, Entrepreneurship

Re: John and Fawn, each drinking at a constant pace, can finish
[#permalink]
Show Tags
17 Feb 2012, 21:11
Hi, I think the OA is incorrect. I think it should be D Statement 1 : Each takes 30 hours to finish the case independently => John can finish a case in 30 hours hence sufficient Statement 2 : J = F+10 1/J + 1/F = 1/12 1/(F+10) + 1/F = 1/12 Solving the quadratic equation we get F = 20 / F =6. Work time problem hence 6 is eliminated Hence we can find J Hence Statement 2 is sufficient Hence D
_________________
Giving +1 kudos is a better way of saying 'Thank You'.



Manager
Joined: 31 Jan 2012
Posts: 70

Re: John and Fawn, each drinking at a constant pace, can finish
[#permalink]
Show Tags
17 Feb 2012, 21:20
Statement 1 can't be correct because you don't know who out of the 2 is the faster drinker... John could drink faster than his friend or vice versa. Also you definition of average is wrong... Average mean A+B/2. A and B does not have to be the same. It could take John 50 mins to finish and Fawn 10 mins The average would still be 30



Manager
Status: Retaking next month
Affiliations: None
Joined: 05 Mar 2011
Posts: 153
Location: India
Concentration: Marketing, Entrepreneurship
GPA: 3.01
WE: Sales (Manufacturing)

Re: John and Fawn, each drinking at a constant pace, can finish
[#permalink]
Show Tags
17 Feb 2012, 21:35
kys123 wrote: Statement 1 can't be correct because you don't know who out of the 2 is the faster drinker... John could drink faster than his friend or vice versa. Also you definition of average is wrong... Average mean A+B/2. A and B does not have to be the same. It could take John 50 mins to finish and Fawn 10 mins The average would still be 30 Faster drinker !!!! where does that come from??? St 1 Clearly states that "The average time it would take both to finish independently is 30 hours". This clearly Implies : Rj = 1/30 , Rf= 1/30. In this case when they work together total time to finish this will be t=15. But in the question they finish the work in 12 hrs. How come. The 1st statement is contradicting the question itself. Are there any Gaps or am I misinterpreting.



Manager
Status: Employed
Joined: 17 Nov 2011
Posts: 82
Location: Pakistan
Concentration: International Business, Marketing
GPA: 3.2
WE: Business Development (Internet and New Media)

Re: John and Fawn, each drinking at a constant pace, can finish
[#permalink]
Show Tags
Updated on: 18 Feb 2012, 02:57
GMATPASSION wrote: kys123 wrote: Statement 1 can't be correct because you don't know who out of the 2 is the faster drinker... John could drink faster than his friend or vice versa. Also you definition of average is wrong... Average mean A+B/2. A and B does not have to be the same. It could take John 50 mins to finish and Fawn 10 mins The average would still be 30 Faster drinker !!!! where does that come from??? St 1 Clearly states that "The average time it would take both to finish independently is 30 hours". This clearly Implies : Rj = 1/30 , Rf= 1/30. In this case when they work together total time to finish this will be t=15. But in the question they finish the work in 12 hrs. How come. The 1st statement is contradicting the question itself. Are there any Gaps or am I misinterpreting. Yes Mate. There is a big gap. How do you identify who is faster and who is slower. Given the information you cannot decide. The question is asking for an individual's time. Its the average time. Imagine the average time is \(30\) hrs for both of them. This could happen in so many ways. The two values could be \(20\) & \(40\) or the two values could be \(10\) & \(50\). More importantly, we wouldn't know who accounted for which. The average of both these scenarios would be \(30\), NO? An infinite number of possibilities exist with that "Average" information alone. Only Statement B tells us the "weight" of each contributor and tells us who was quicker. That alone should be enough information for you to pick B (alongwith the fact that B limits to one variable alone), in most cases, unless it is another one of those GMAT trick questions However, this one clearly isn't and Statement B is hence enough. Since we know the relative weights of each contributor, B wins and is SUFFICIENT alone. I suggest you look up "Weighted Averages" on Wikipedia or some good Mathematics site. By the way Bunuel has composed an amazing Maths Book on the Gmat Club Forum and the more I read it, the more I realize how precise his understanding of the GMAT Quantitative section is. I seriously suggest you read it up. It will help clear a lot of tricky logic gaps. Hope I was able to explain it to you. And thanks Bunuel for pointing the error in my post.
_________________
"Nowadays, people know the price of everything, and the value of nothing." Oscar Wilde
Originally posted by omerrauf on 18 Feb 2012, 00:50.
Last edited by omerrauf on 18 Feb 2012, 02:57, edited 5 times in total.



Math Expert
Joined: 02 Sep 2009
Posts: 50002

Re: John and Fawn, each drinking at a constant pace, can finish
[#permalink]
Show Tags
18 Feb 2012, 00:59
omerrauf wrote: GMATPASSION wrote: kys123 wrote: Statement 1 can't be correct because you don't know who out of the 2 is the faster drinker... John could drink faster than his friend or vice versa. Also you definition of average is wrong... Average mean A+B/2. A and B does not have to be the same. It could take John 50 mins to finish and Fawn 10 mins The average would still be 30 Faster drinker !!!! where does that come from??? St 1 Clearly states that "The average time it would take both to finish independently is 30 hours". This clearly Implies : Rj = 1/30 , Rf= 1/30. In this case when they work together total time to finish this will be t=15. But in the question they finish the work in 12 hrs. How come. The 1st statement is contradicting the question itself. Are there any Gaps or am I misinterpreting. Yes Mate. There is a big gap. Its the average time. Imagine the average time is 30 hrs for both of them. This could happen in so many ways. The two values could be \(20\) & \(40\) or the two values could be \(10\) & \(50\). The average of both these scenarios would be \(30\), NO? An infinite number of possibilities exist with that "Average" information alone. Only Statement B tells us the "weight" of each contributor and that alone should be enough information for you to pick B, in most cases, unless it is another one of those GMAT trick questions However, this one clearly isn't and Statement B is hence enough. Since we know the relative weights of each contributor, B wins and is SUFFICIENT alone. Hope I was able to explain it to you. Check the solution above: for (1) there exist only TWO combination of J and F, not more.
_________________
New to the Math Forum? Please read this: Ultimate GMAT Quantitative Megathread  All You Need for Quant  PLEASE READ AND FOLLOW: 12 Rules for Posting!!! Resources: GMAT Math Book  Triangles  Polygons  Coordinate Geometry  Factorials  Circles  Number Theory  Remainders; 8. Overlapping Sets  PDF of Math Book; 10. Remainders  GMAT Prep Software Analysis  SEVEN SAMURAI OF 2012 (BEST DISCUSSIONS)  Tricky questions from previous years.
Collection of Questions: PS: 1. Tough and Tricky questions; 2. Hard questions; 3. Hard questions part 2; 4. Standard deviation; 5. Tough Problem Solving Questions With Solutions; 6. Probability and Combinations Questions With Solutions; 7 Tough and tricky exponents and roots questions; 8 12 Easy Pieces (or not?); 9 Bakers' Dozen; 10 Algebra set. ,11 Mixed Questions, 12 Fresh Meat DS: 1. DS tough questions; 2. DS tough questions part 2; 3. DS tough questions part 3; 4. DS Standard deviation; 5. Inequalities; 6. 700+ GMAT Data Sufficiency Questions With Explanations; 7 Tough and tricky exponents and roots questions; 8 The Discreet Charm of the DS; 9 Devil's Dozen!!!; 10 Number Properties set., 11 New DS set.
What are GMAT Club Tests? Extrahard Quant Tests with Brilliant Analytics



Manager
Status: Employed
Joined: 17 Nov 2011
Posts: 82
Location: Pakistan
Concentration: International Business, Marketing
GPA: 3.2
WE: Business Development (Internet and New Media)

Re: John and Fawn, each drinking at a constant pace, can finish
[#permalink]
Show Tags
18 Feb 2012, 01:05
Yup. Right on Bunuel... My Bad....
_________________
"Nowadays, people know the price of everything, and the value of nothing." Oscar Wilde



Manager
Joined: 25 Nov 2011
Posts: 201
Location: India
Concentration: Technology, General Management
GPA: 3.95
WE: Information Technology (Computer Software)

Re: John and Fawn, each drinking at a constant pace, can finish
[#permalink]
Show Tags
18 Feb 2012, 04:12
Bunuel wrote: But even though the formal answer to the question is B, this is not a realistic GMAT question, as: on the GMAT, two data sufficiency statements always provide TRUE information and these statements never contradict each other. In our question, from (2) we have that the average time is (30+20)/2=25 and (1) states that it's 30, so the statements clearly contradict each other.
In order it to be a realistic GMAT question (1) should read: The average time it would take John to finish the case drinking alone and Fawn to finish the case drinking alone is 25 hours. In this case for (1) we'll have: 1/J + 1/(50J) = 1/12 > J=30 (so F=20 > J>F) or J=20 (so F=30 > J<F). Statements don't contradict and (1) is still insufficient.
Hope it's clear.
Actually MGMAT flashcards did not provide the first statement. I made it up so that the whole question looks like a GMAT question. But I did not think of the point you mentioned. Great man
_________________
 Aravind Chembeti



Director
Joined: 07 Aug 2011
Posts: 540
Concentration: International Business, Technology

Re: John and Fawn, each drinking at a constant pace, can finish
[#permalink]
Show Tags
27 Dec 2014, 12:16
Bunuel wrote: Chembeti wrote: John and Fawn, each drinking at a constant pace, can finish a case of soda together in 12 hours. How fast can John, drinking alone, finish the case? 1) The average time it would take both to finish independently is 30 hours. 2) It would take John 10 more hours to finish the case drinking alone than it would for Fawn to finish the case. This is actually from MGMAT flash cards. Looked interesting and hence I posted after modifying it a bit (I added a new statement). John and Fawn, each drinking at a constant pace, can finish a case of soda together in 12 hours. How fast can John, drinking alone, finish the case?Given: 1/J + 1/F = 1/12 (1) The average time it would take both to finish independently is 30 hours > J+F=60. Now, since we don't know which one drinks faster then even if we substitute F with 60J (1/J + 1/(60J) = 1/12) we must get two different answers for J and F: J<F and J>F. Not sufficient. (2) It would take John 10 more hours to finish the case drinking alone than it would for Fawn to finish the case > F=J10 > 1/J + 1/(J10) = 1/12 > J=4 (not a valid solution as F in this case is negative) and J=30 ( F=20). Sufficient. Now, technically the answer should be B, as Statement (2) ALONE is sufficient, but statement (1) alone is not sufficient.But even though the formal answer to the question is B, this is not a realistic GMAT question, as: on the GMAT, two data sufficiency statements always provide TRUE information and these statements never contradict each other. In our question, from (2) we have that the average time is (30+20)/2=25 and (1) states that it's 30, so the statements clearly contradict each other. In order it to be a realistic GMAT question (1) should read: The average time it would take John to finish the case drinking alone and Fawn to finish the case drinking alone is 25 hours. In this case for (1) we'll have: 1/J + 1/(50J) = 1/12 > J=30 (so F=20 > J>F) or J=20 (so F=30 > J<F). Statements don't contradict and (1) is still insufficient. Hope it's clear. Hi Bunnel , (1) The average time it would take both to finish independently is 30 hours > J+F=60. Now, if we substitute F with 60J (1/J + 1/(60J) = 1/12) we will get a quadratic in J with one +ive and one ive Solution for J . Clearly J cannot be negative . so this statement should be sufficient . no ? Please advise , if i am missing something . thanks
_________________
Thanks, Lucky
_______________________________________________________ Kindly press the to appreciate my post !!



Math Expert
Joined: 02 Sep 2009
Posts: 50002

Re: John and Fawn, each drinking at a constant pace, can finish
[#permalink]
Show Tags
28 Dec 2014, 06:16
Lucky2783 wrote: Bunuel wrote: Chembeti wrote: John and Fawn, each drinking at a constant pace, can finish a case of soda together in 12 hours. How fast can John, drinking alone, finish the case? 1) The average time it would take both to finish independently is 30 hours. 2) It would take John 10 more hours to finish the case drinking alone than it would for Fawn to finish the case. This is actually from MGMAT flash cards. Looked interesting and hence I posted after modifying it a bit (I added a new statement). John and Fawn, each drinking at a constant pace, can finish a case of soda together in 12 hours. How fast can John, drinking alone, finish the case?Given: 1/J + 1/F = 1/12 (1) The average time it would take both to finish independently is 30 hours > J+F=60. Now, since we don't know which one drinks faster then even if we substitute F with 60J (1/J + 1/(60J) = 1/12) we must get two different answers for J and F: J<F and J>F. Not sufficient. (2) It would take John 10 more hours to finish the case drinking alone than it would for Fawn to finish the case > F=J10 > 1/J + 1/(J10) = 1/12 > J=4 (not a valid solution as F in this case is negative) and J=30 ( F=20). Sufficient. Now, technically the answer should be B, as Statement (2) ALONE is sufficient, but statement (1) alone is not sufficient.But even though the formal answer to the question is B, this is not a realistic GMAT question, as: on the GMAT, two data sufficiency statements always provide TRUE information and these statements never contradict each other. In our question, from (2) we have that the average time is (30+20)/2=25 and (1) states that it's 30, so the statements clearly contradict each other. In order it to be a realistic GMAT question (1) should read: The average time it would take John to finish the case drinking alone and Fawn to finish the case drinking alone is 25 hours. In this case for (1) we'll have: 1/J + 1/(50J) = 1/12 > J=30 (so F=20 > J>F) or J=20 (so F=30 > J<F). Statements don't contradict and (1) is still insufficient. Hope it's clear. Hi Bunnel , (1) The average time it would take both to finish independently is 30 hours > J+F=60. Now, if we substitute F with 60J (1/J + 1/(60J) = 1/12) we will get a quadratic in J with one +ive and one ive Solution for J . Clearly J cannot be negative . so this statement should be sufficient . no ? Please advise , if i am missing something . thanks Did you try to actually solve? You'd get two solutions for J, both positive: ~17 and ~43.
_________________
New to the Math Forum? Please read this: Ultimate GMAT Quantitative Megathread  All You Need for Quant  PLEASE READ AND FOLLOW: 12 Rules for Posting!!! Resources: GMAT Math Book  Triangles  Polygons  Coordinate Geometry  Factorials  Circles  Number Theory  Remainders; 8. Overlapping Sets  PDF of Math Book; 10. Remainders  GMAT Prep Software Analysis  SEVEN SAMURAI OF 2012 (BEST DISCUSSIONS)  Tricky questions from previous years.
Collection of Questions: PS: 1. Tough and Tricky questions; 2. Hard questions; 3. Hard questions part 2; 4. Standard deviation; 5. Tough Problem Solving Questions With Solutions; 6. Probability and Combinations Questions With Solutions; 7 Tough and tricky exponents and roots questions; 8 12 Easy Pieces (or not?); 9 Bakers' Dozen; 10 Algebra set. ,11 Mixed Questions, 12 Fresh Meat DS: 1. DS tough questions; 2. DS tough questions part 2; 3. DS tough questions part 3; 4. DS Standard deviation; 5. Inequalities; 6. 700+ GMAT Data Sufficiency Questions With Explanations; 7 Tough and tricky exponents and roots questions; 8 The Discreet Charm of the DS; 9 Devil's Dozen!!!; 10 Number Properties set., 11 New DS set.
What are GMAT Club Tests? Extrahard Quant Tests with Brilliant Analytics



CEO
Joined: 08 Jul 2010
Posts: 2559
Location: India
GMAT: INSIGHT
WE: Education (Education)

Re: John and Fawn, each drinking at a constant pace, can finish
[#permalink]
Show Tags
10 Nov 2016, 00:45
Chembeti wrote: John and Fawn, each drinking at a constant pace, can finish a case of soda together in 12 hours. How fast can John, drinking alone, finish the case? 1) The average time it would take both to finish independently is 30 hours. 2) It would take John 10 more hours to finish the case drinking alone than it would for Fawn to finish the case. This is actually from MGMAT flash cards. Looked interesting and hence I posted after modifying it a bit (I added a new statement). Answer: Option B Please check the solution as attached
Attachments
File comment: www.GMATinsight.com
4.jpg [ 66.72 KiB  Viewed 1400 times ]
_________________
Prosper!!! GMATinsight Bhoopendra Singh and Dr.Sushma Jha email: info@GMATinsight.com I Call us : +919999687183 / 9891333772 Online OneonOne Skype based classes and Classroom Coaching in South and West Delhi http://www.GMATinsight.com/testimonials.html
ACCESS FREE GMAT TESTS HERE:22 ONLINE FREE (FULL LENGTH) GMAT CAT (PRACTICE TESTS) LINK COLLECTION



NonHuman User
Joined: 09 Sep 2013
Posts: 8462

Re: John and Fawn, each drinking at a constant pace, can finish
[#permalink]
Show Tags
20 Mar 2018, 05:05
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.
_________________
GMAT Books  GMAT Club Tests  Best Prices on GMAT Courses  GMAT Mobile App  Math Resources  Verbal Resources




Re: John and Fawn, each drinking at a constant pace, can finish &nbs
[#permalink]
20 Mar 2018, 05:05






