December 20, 2018 December 20, 2018 10:00 PM PST 11:00 PM PST This is the most inexpensive and attractive price in the market. Get the course now! December 22, 2018 December 22, 2018 07:00 AM PST 09:00 AM PST Attend this webinar to learn how to leverage Meaning and Logic to solve the most challenging Sentence Correction Questions.
Author 
Message 
TAGS:

Hide Tags

Senior Manager
Joined: 18 Sep 2009
Posts: 283

Is the number of members of Club X greater than the number
[#permalink]
Show Tags
05 Mar 2012, 17:06
Question Stats:
72% (01:22) correct 28% (01:26) wrong based on 2157 sessions
HideShow timer Statistics
Is the number of members of Club X greater than the number of members of Club Y ? (1) Of the members of Club X, 20 percent are also members of Club Y. (2) Of the members of Club Y, 30 percent are also members of Club X. can we use matrix approach for this question. every body is saying: 0.20x=0.30y x/y=3/2 so x>y.
what i know is ratios are not enough to compare two quantities. I am very bad at Ratio and proportions. Please explain
Official Answer and Stats are available only to registered users. Register/ Login.




Math Expert
Joined: 02 Sep 2009
Posts: 51307

Re: Is the number of members of Club X greater than the number
[#permalink]
Show Tags
05 Mar 2012, 21:03
TomB wrote: Is the number of members of Club X greater than the number of members of Club Y ? (1)Of the members of Club X, 20 percent are also members of Club Y. (2)Of the members of Club Y, 30 percent are also members of Club X.
can we use matrix approach for this question. every body is saying: 0.20x=0.30y x/y=3/2 so x>y.
what i know is ratios are not enough to compare two quantities. I am very bad at Ratio and proportions. Please explain Is the number of members of Club X greater than the number of members of Club Y?(1) Of the members of Club X, 20 percent are also members of Club Y > 20% of X are members of both X and Y > 0.2X={both}. Not sufficient. (2) Of the members of Club Y, 30 percent are also members of Club X > 30% of Y are members of both X and Y > 0.3Y={both}. Not sufficient. (1)+(2) 0.2X={both}=0.3Y > X/Y=3/2 > X>Y. Sufficient. Answer: C. TomB wrote: 0.20x=0.30y x/y=3/2 so x>y.
what i know is ratios are not enough to compare two quantities. I am very bad at Ratio and proportions. Please explain If x and y are both negative then x<y, for example: x=3<2=y and if x and y are both positive then x>y. So generally you are right x/y=3/2 is NOT enough to say whether x>y. Though in our case since x and y represent # of people then we know that they must be positive integers, so case 1 is ruled out and we CAN say that x>y. 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




Intern
Joined: 07 Feb 2013
Posts: 12
GMAT 1: 650 Q48 V32 GMAT 2: 730 Q49 V41
WE: Engineering (Other)

Re: Is the number of members of Club X greater than the number
[#permalink]
Show Tags
15 Jun 2013, 09:47
clearly A or B were insufficient.
my process : Total members = Members of X only (Say A) + Members of Y Only (Say B) + Members of Both = A + B + both Now from the statements both= either 0.2A or 0.3B Total = A + B + 0.2A or = A + B + 0.3B Equating both A + B + 0.2A= A + B +0.3B 0.2A=0.3B A=1.5B => X>Y Answer C




Intern
Joined: 26 Mar 2012
Posts: 27
Location: United States
Concentration: Technology, General Management
GPA: 3.77
WE: Engineering (Computer Software)

Re: Is the number of members of Club X greater than the number
[#permalink]
Show Tags
08 May 2012, 05:35
From what I can deduce, we can make a table for the two possibilities (table formatting is a mess, sorry) :
....................Club Y..........NOT Club Y  Club X...............? .............................. X NOT Club X.......................................... .......................Y Let X be the number of members in club X and let Y be the number of members in club Y. Question stem asks whether X>Y?
1. Top left corner contains info about number common number of members in both clubs. Thus, ? = .2 X But we can't decide whether X>Y. NOT SUFFICIENT.
2. Top left corner contains info about number common number of members in both clubs. Thus, ? = .3 Y But we can't decide whether X>Y. NOT SUFFICIENT.
Combine the two, ? = .2X = .3 Y. Since number of members is a positive integer, we know the answer to X>Y. SUFFICIENT.
Answer C.



Manager
Joined: 23 Aug 2011
Posts: 70

Re: Is the number of members of Club X greater than the number
[#permalink]
Show Tags
14 Aug 2012, 02:41
Using the table it can also be solved easily. As the individual entries result in insufficient data, options A/B/D can be eliminated. Combining both the entries we can observe under the column "members of X and members of Y" ,the value of .2X=.3Y, which answers X>Y .Hence C is the ans.
Attachments
tb.jpg [ 18.72 KiB  Viewed 33051 times ]
_________________
Whatever one does in life is a repetition of what one has done several times in one's life! If my post was worth it, then i deserve kudos



Current Student
Joined: 10 Nov 2013
Posts: 19
Location: United States
Concentration: Healthcare, Strategy
WE: Information Technology (Health Care)

Re: Is the number of members of Club X greater than the number
[#permalink]
Show Tags
03 Dec 2013, 21:31
nanz236 wrote: clearly A or B were insufficient.
my process : Total members = Members of X only (Say A) + Members of Y Only (Say B) + Members of Both = A + B + both Now from the statements both= either 0.2A or 0.3B Total = A + B + 0.2A or = A + B + 0.3B Equating both A + B + 0.2A= A + B +0.3B 0.2A=0.3B A=1.5B => X>Y Answer C yes, i agree with your approach. It was very hard for me to understand how can we equate 0.2x = 0.3y. I do not seem to get the correlation between these 2 statements to equate 0.2Y = 0.3 Y. Thanks!



Intern
Joined: 27 Aug 2009
Posts: 48

Re: Is the number of members of Club X greater than the number
[#permalink]
Show Tags
02 Jul 2014, 14:44



Intern
Joined: 22 Feb 2014
Posts: 27

Re: Is the number of members of Club X greater than the number
[#permalink]
Show Tags
30 Jul 2014, 07:07
Bunuel wrote: TomB wrote: Is the number of members of Club X greater than the number of members of Club Y ? (1)Of the members of Club X, 20 percent are also members of Club Y. (2)Of the members of Club Y, 30 percent are also members of Club X.
can we use matrix approach for this question. every body is saying: 0.20x=0.30y x/y=3/2 so x>y.
what i know is ratios are not enough to compare two quantities. I am very bad at Ratio and proportions. Please explain Is the number of members of Club X greater than the number of members of Club Y?(1) Of the members of Club X, 20 percent are also members of Club Y > 20% of X are members of both X and Y > 0.2X={both}. Not sufficient. (2) Of the members of Club Y, 30 percent are also members of Club X > 30% of Y are members of both X and Y > 0.3Y={both}. Not sufficient. (1)+(2) 0.2X={both}=0.3Y > X/Y=3/2 > X>Y. Sufficient. Answer: C. TomB wrote: 0.20x=0.30y x/y=3/2 so x>y.
what i know is ratios are not enough to compare two quantities. I am very bad at Ratio and proportions. Please explain If x and y are both negative then x<y, for example: x=3<2=y and if x and y are both positive then x>y. So generally you are right x/y=3/2 is NOT enough to say whether x>y. Though in our case since x and y represent # of people then we know that they must be positive integers, so case 1 is ruled out and we CAN say that x>y. Hope it's clear. Hi Can I solve this kind of question by assuming total numbers?? for example while combining 1 and 2: I assumed 100 total members then assumed two scenarios : 1: X group: 30 members: 20% in Y , 51 in X 2 Y group: 70 : 70+6 = 76 30% IN X The same way vice versa situation where X is 70 and Y is 30: By doing this way I got E.... cAN you pls explain why my approach is wrong???



Math Expert
Joined: 02 Sep 2009
Posts: 51307

Re: Is the number of members of Club X greater than the number
[#permalink]
Show Tags
30 Jul 2014, 08:03
GGMAT760 wrote: Bunuel wrote: TomB wrote: Is the number of members of Club X greater than the number of members of Club Y ? (1)Of the members of Club X, 20 percent are also members of Club Y. (2)Of the members of Club Y, 30 percent are also members of Club X.
can we use matrix approach for this question. every body is saying: 0.20x=0.30y x/y=3/2 so x>y.
what i know is ratios are not enough to compare two quantities. I am very bad at Ratio and proportions. Please explain Is the number of members of Club X greater than the number of members of Club Y?(1) Of the members of Club X, 20 percent are also members of Club Y > 20% of X are members of both X and Y > 0.2X={both}. Not sufficient. (2) Of the members of Club Y, 30 percent are also members of Club X > 30% of Y are members of both X and Y > 0.3Y={both}. Not sufficient. (1)+(2) 0.2X={both}=0.3Y > X/Y=3/2 > X>Y. Sufficient. Answer: C. TomB wrote: 0.20x=0.30y x/y=3/2 so x>y.
what i know is ratios are not enough to compare two quantities. I am very bad at Ratio and proportions. Please explain If x and y are both negative then x<y, for example: x=3<2=y and if x and y are both positive then x>y. So generally you are right x/y=3/2 is NOT enough to say whether x>y. Though in our case since x and y represent # of people then we know that they must be positive integers, so case 1 is ruled out and we CAN say that x>y. Hope it's clear. Hi Can I solve this kind of question by assuming total numbers?? for example while combining 1 and 2: I assumed 100 total members then assumed two scenarios : 1: X group: 30 members: 20% in Y , 51 in X 2 Y group: 70 : 70+6 = 76 30% IN X The same way vice versa situation where X is 70 and Y is 30: By doing this way I got E.... cAN you pls explain why my approach is wrong??? Your approach does not make much sense. The statements give certain relationship between the numbers in X and Y, you cannot assume arbitrary values for them. Also, if there are 30 members in X, then 20% of them, so 6 members, are also in Y. Now, we also know that these 6 members comprise 30% of Y, so 0.3Y=6 > Y=20 > X=30 > Y=20.
_________________
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



Intern
Joined: 08 Dec 2014
Posts: 5
Concentration: Sustainability, Entrepreneurship

Re: Is the number of members of Club X greater than the number
[#permalink]
Show Tags
21 Jan 2015, 06:27
This question was frustrating to me. My answer is E because there was no mention of the amount of people in each club for instance: club A has 10 people, club B has 20 people
Overlap= 6B+2A
Club A then has 8 members Club B has 14 members or if the numbers are different then Club A could have more leading to both being insufficient.
Is the assumption that there are both the same number of people in each club to start or is this a flaw??



Math Expert
Joined: 02 Sep 2009
Posts: 51307

Re: Is the number of members of Club X greater than the number
[#permalink]
Show Tags
21 Jan 2015, 07:55



EMPOWERgmat Instructor
Status: GMAT Assassin/CoFounder
Affiliations: EMPOWERgmat
Joined: 19 Dec 2014
Posts: 13111
Location: United States (CA)

Re: Is the number of members of Club X greater than the number
[#permalink]
Show Tags
21 Jan 2015, 13:12
Hi All, This DS question can be solved by TESTing VALUES. We're asked if the number of members of Club X is greater than the number of members of Club Y? This is a YES/NO question. In these sorts of situations, it's common for some members to belong to BOTH Clubs, so we have to keep careful track of the numbers and possibilities.... Fact 1: 20% of the members of Club X are ALSO members of Club Y IF... Club X has 100 members, then 20 of those members ALSO belong to Club Y. IF Club Y has 0 unique members, then the answer to the question is YES. IF Club Y as 1,000 unique members, then the answer to the question is NO. Fact 1 is INSUFFICIENT Fact 2: 30% of the members of Club Y are ALSO members of Club X This Fact offers the same general logic as Fact 1 (above). Without knowing the number of unique members in Club X, the answer to the question could be either YES or NO. Fact 2 is INSUFFICIENT Combined, we know... 20% of the members of Club X are ALSO members of Club Y 30% of the members of Club Y are ALSO members of Club X These specific members are the SAME PEOPLE... This means that .2(X) = .3(Y) 2X = 3Y X = (3/2)(Y) This means that X MUST be greater than Y, so the answer to the question is ALWAYS YES. Combined, SUFFICIENT Final Answer: GMAT assassins aren't born, they're made, Rich
_________________
760+: Learn What GMAT Assassins Do to Score at the Highest Levels Contact Rich at: Rich.C@empowergmat.com
Rich Cohen
CoFounder & GMAT Assassin
Special Offer: Save $75 + GMAT Club Tests Free
Official GMAT Exam Packs + 70 Pt. Improvement Guarantee www.empowergmat.com/
*****Select EMPOWERgmat Courses now include ALL 6 Official GMAC CATs!*****



Intern
Joined: 25 Mar 2015
Posts: 7

Re: Is the number of members of Club X greater than the number
[#permalink]
Show Tags
20 Jul 2015, 22:12
Bunuel wrote: GGMAT760 wrote: Bunuel wrote: Is the number of members of Club X greater than the number of members of Club Y ? Hi Can I solve this kind of question by assuming total numbers?? for example while combining 1 and 2: I assumed 100 total members then assumed two scenarios : 1: X group: 30 members: 20% in Y , 51 in X 2 Y group: 70 : 70+6 = 76 30% IN X
The same way vice versa situation where X is 70 and Y is 30: By doing this way I got E.... cAN you pls explain why my approach is wrong??? Your approach does not make much sense. The statements give certain relationship between the numbers in X and Y, you cannot assume arbitrary values for them. Also, if there are 30 members in X, then 20% of them, so 6 members, are also in Y. Now, we also know that these 6 members comprise 30% of Y, so 0.3Y=6 > Y=20 > X=30 > Y=20. If I adopt the method of assuming numbers, would this make sense Statement 1: Assume X to have 100 members. therefore, 20% of 100 = 20 20 members of X also belong to Y Insuff. Statement 2: Assume Y to have 100 members. 30% of Y= 30 30 members of Y also belong to X Insuff. 1+2: We know: 1. 30% of Y belong to X; and 2. 20 members of X belong to Y Therefore 30% of (Y) = 20 from which we get a value of Y>X.



Intern
Joined: 20 Jul 2015
Posts: 5
Location: Canada
GPA: 3
WE: Account Management (Consumer Products)

Re: Is the number of members of Club X greater than the number
[#permalink]
Show Tags
19 Dec 2015, 20:28
EMPOWERgmatRichC wrote: Hi All, This DS question can be solved by TESTing VALUES. We're asked if the number of members of Club X is greater than the number of members of Club Y? This is a YES/NO question. In these sorts of situations, it's common for some members to belong to BOTH Clubs, so we have to keep careful track of the numbers and possibilities.... Fact 1: 20% of the members of Club X are ALSO members of Club Y IF... Club X has 100 members, then 20 of those members ALSO belong to Club Y. IF Club Y has 0 unique members, then the answer to the question is YES. IF Club Y as 1,000 unique members, then the answer to the question is NO. Fact 1 is INSUFFICIENT Fact 2: 30% of the members of Club Y are ALSO members of Club X This Fact offers the same general logic as Fact 1 (above). Without knowing the number of unique members in Club X, the answer to the question could be either YES or NO. Fact 2 is INSUFFICIENT Combined, we know... 20% of the members of Club X are ALSO members of Club Y 30% of the members of Club Y are ALSO members of Club X These specific members are the SAME PEOPLE... This means that .2(X) = .3(Y) 2X = 3Y X = (3/2)(Y) This means that X MUST be greater than Y, so the answer to the question is ALWAYS YES. Combined, SUFFICIENT Final Answer: GMAT assassins aren't born, they're made, Rich I'm still quite not getting it: What if Club X had 100 people, 20 of whom are also in Club Y. But then Club Y had 50 people, 15 of whom are also in Club X. But then you can reverse those values, and you could say what if Club x had 50 people, 10 of whom are in Club y, and Club y had 100 people, 30 of whom are in Club X. Why does this above logic not make sense (sets the answer as E)? It must not, as the answer is C. EDIT: nevermind, I just got it. You can't make up those 2 values as it results in the Club X+Y group having two different values, when they are 1 group. Clearly didn't follow that...I'll leave my thinking and train of thought incase it helps someone else.



EMPOWERgmat Instructor
Status: GMAT Assassin/CoFounder
Affiliations: EMPOWERgmat
Joined: 19 Dec 2014
Posts: 13111
Location: United States (CA)

Re: Is the number of members of Club X greater than the number
[#permalink]
Show Tags
20 Dec 2015, 18:38
Hi oseebhai, The work that you did in your 'example' is actually really USEFUL  once you notice that the two numbers MUST be the same, you have the proof that the values of X and Y ARE related (so the answer must be C). Sometimes the work that you have to do in a DS questions helps you to prove what is NOT possible  and while it might not be the most straightforward approach, it can still help you to still answer the question correctly. GMAT assassins aren't born, they're made, Rich
_________________
760+: Learn What GMAT Assassins Do to Score at the Highest Levels Contact Rich at: Rich.C@empowergmat.com
Rich Cohen
CoFounder & GMAT Assassin
Special Offer: Save $75 + GMAT Club Tests Free
Official GMAT Exam Packs + 70 Pt. Improvement Guarantee www.empowergmat.com/
*****Select EMPOWERgmat Courses now include ALL 6 Official GMAC CATs!*****



Intern
Joined: 27 Oct 2015
Posts: 13

Re: Is the number of members of Club X greater than the number
[#permalink]
Show Tags
17 Feb 2016, 09:50
Bunuel wrote: TomB wrote: Is the number of members of Club X greater than the number of members of Club Y ? (1)Of the members of Club X, 20 percent are also members of Club Y. (2)Of the members of Club Y, 30 percent are also members of Club X.
can we use matrix approach for this question. every body is saying: 0.20x=0.30y x/y=3/2 so x>y.
what i know is ratios are not enough to compare two quantities. I am very bad at Ratio and proportions. Please explain Is the number of members of Club X greater than the number of members of Club Y?(1) Of the members of Club X, 20 percent are also members of Club Y > 20% of X are members of both X and Y > 0.2X={both}. Not sufficient. (2) Of the members of Club Y, 30 percent are also members of Club X > 30% of Y are members of both X and Y > 0.3Y={both}. Not sufficient. (1)+(2) 0.2X={both}=0.3Y > X/Y=3/2 > X>Y. Sufficient. Answer: C. TomB wrote: 0.20x=0.30y x/y=3/2 so x>y.
what i know is ratios are not enough to compare two quantities. I am very bad at Ratio and proportions. Please explain If x and y are both negative then x<y, for example: x=3<2=y and if x and y are both positive then x>y. So generally you are right x/y=3/2 is NOT enough to say whether x>y. Though in our case since x and y represent # of people then we know that they must be positive integers, so case 1 is ruled out and we CAN say that x>y. Hope it's clear. Dear, Bunuel! Please tell me whether my reasoning is correct? Thanks
Attachments
yyyyyyyyyyyyyyyyyy.JPG [ 23.82 KiB  Viewed 22352 times ]



Manager
Joined: 19 Oct 2016
Posts: 70
Location: India
Concentration: Marketing, Leadership
GMAT 1: 580 Q46 V24 GMAT 2: 540 Q39 V25 GMAT 3: 660 Q48 V34
GPA: 3.15
WE: Psychology and Counseling (Health Care)

Re: Is the number of members of Club X greater than the number
[#permalink]
Show Tags
04 Nov 2016, 07:53
TomB wrote: Is the number of members of Club X greater than the number of members of Club Y ?
(1) Of the members of Club X, 20 percent are also members of Club Y. (2) Of the members of Club Y, 30 percent are also members of Club X.
can we use matrix approach for this question. every body is saying: 0.20x=0.30y x/y=3/2 so x>y.
what i know is ratios are not enough to compare two quantities. I am very bad at Ratio and proportions. Please explain Make a Venn Diagram. Statement one states that 20% of X are also in Y. Insufficient. Statement two states that 30% of Y are also in X. Insufficient. When you combine them you can see from drawing a venn diagram that the number of people in both groups have to be the same. Since 20% of X has to equal 30% of Y, you can set Y to 100. 30% of 100 is 30 so that will be the both section. Since 30 has to equal 20% of X, just multiple 5 x 30. 150 is X 100 is y and 30 is both. X bigger.



Manager
Joined: 26 Mar 2017
Posts: 119

Re: Is the number of members of Club X greater than the number
[#permalink]
Show Tags
29 May 2017, 09:15
studentsensual wrote: Bunuel wrote: TomB wrote: Is the number of members of Club X greater than the number of members of Club Y ? (1)Of the members of Club X, 20 percent are also members of Club Y. (2)Of the members of Club Y, 30 percent are also members of Club X.
can we use matrix approach for this question. every body is saying: 0.20x=0.30y x/y=3/2 so x>y.
what i know is ratios are not enough to compare two quantities. I am very bad at Ratio and proportions. Please explain Is the number of members of Club X greater than the number of members of Club Y?(1) Of the members of Club X, 20 percent are also members of Club Y > 20% of X are members of both X and Y > 0.2X={both}. Not sufficient. (2) Of the members of Club Y, 30 percent are also members of Club X > 30% of Y are members of both X and Y > 0.3Y={both}. Not sufficient. (1)+(2) 0.2X={both}=0.3Y > X/Y=3/2 > X>Y. Sufficient. Answer: C. TomB wrote: 0.20x=0.30y x/y=3/2 so x>y.
what i know is ratios are not enough to compare two quantities. I am very bad at Ratio and proportions. Please explain If x and y are both negative then x<y, for example: x=3<2=y and if x and y are both positive then x>y. So generally you are right x/y=3/2 is NOT enough to say whether x>y. Though in our case since x and y represent # of people then we know that they must be positive integers, so case 1 is ruled out and we CAN say that x>y. Hope it's clear. Dear, Bunuel! Please tell me whether my reasoning is correct? Thanks used the same approach but not sure whether this is correct I guess if we also take into account that 20% of X = 30 % of Y than your reasoning is correct but without this information we don't know whether 80% of X > 70% of Y (at least in my opinion)
_________________
I hate long and complicated explanations!



Intern
Joined: 25 Nov 2016
Posts: 21
Location: India
WE: Law (NonProfit and Government)

Re: Is the number of members of Club X greater than the number
[#permalink]
Show Tags
17 Aug 2017, 18:52
sukeshap wrote: TomB wrote: Is the number of members of Club X greater than the number of members of Club Y ?
(1) Of the members of Club X, 20 percent are also members of Club Y. (2) Of the members of Club Y, 30 percent are also members of Club X.
Take an example, Both club are having 1000 members, 200 of club X is having membership in Y Insufficient 300 of club Y is having membership in X Insufficient Both together is not giving any conclusion, so the answer is E.
Please correct me if I am wrong If both clubs have 1000 members, x overlap=200,y overlap=300. Since x overlap=y overlap, so x if overlap is increased, then x starts becoming greater than 1000 or if y overlap is reduced then y starts becoming less than 1000. Either way x>y.



Intern
Joined: 27 Apr 2015
Posts: 41

Re: Is the number of members of Club X greater than the number
[#permalink]
Show Tags
27 Feb 2018, 07:38
TomB wrote: Is the number of members of Club X greater than the number of members of Club Y ? (1) Of the members of Club X, 20 percent are also members of Club Y. (2) Of the members of Club Y, 30 percent are also members of Club X. can we use matrix approach for this question. every body is saying: 0.20x=0.30y x/y=3/2 so x>y.
what i know is ratios are not enough to compare two quantities. I am very bad at Ratio and proportions. Please explain Let 1) Number of members of Club X be = x 2) Number of members of Club Y be = y So the question becomes is \(x>y\) Stat 1 Of the members of Club X, 20 percent are also members of Club Y => from Stat 1 we can deduce following => ONLY members of Club X= 0.8x => Members of both Club X & Y= 0.2x Since no more information about x & y. Therefore NOT SUFFICIENT Stat 2 Of the members of Club Y, 30 percent are also members of Club X from Stat 2 we can deduce following => ONLY members of Club Y= 0.7y => Members of both Club X & Y= 0.3y Again Since no more information about x & y. Therefore NOT SUFFICIENT BOTH=> Members of both Club X & Y= 0.2x from (1) => Members of both Club X & Y= 0.3y from (2) => \(0.2x=0.3y\) => OR \(\frac{x}{y}=\frac{0.3}{0.2}=\frac{3}{2}\) => OR \(x=1.5y\) Since x & y are +ve Integers therefore \(x>y\) SUFFICIENT Option C Regards Dinesh




Re: Is the number of members of Club X greater than the number &nbs
[#permalink]
27 Feb 2018, 07:38



Go to page
1 2
Next
[ 28 posts ]



