Author 
Message 
TAGS:

Hide Tags

Intern
Joined: 14 Jun 2011
Posts: 1

Re: Workers are grouped by their areas of expertise, and are [#permalink]
Show Tags
11 Dec 2013, 11:43
Hi, unfortunately i got 62 in total as answer. Would anyone plz explain in which case i've made wrong? For your kind reference, i'm uploading the image of my solution. Attachment:
Problem.jpg [ 31.12 KiB  Viewed 8646 times ]



Math Expert
Joined: 02 Sep 2009
Posts: 46167

Re: Workers are grouped by their areas of expertise, and are [#permalink]
Show Tags
12 Dec 2013, 02:09



Manager
Joined: 20 Oct 2013
Posts: 54

Re: Workers are grouped by their areas of expertise, and are [#permalink]
Show Tags
29 Apr 2014, 11:06
Hi How to identify when the qs is meaning to say exactly 2 overlaps and when the qs means otherwise? This qs seemed like it meant exactly 2.
_________________
Hope to clear it this time!! GMAT 1: 540 Preparing again



Veritas Prep GMAT Instructor
Joined: 16 Oct 2010
Posts: 8100
Location: Pune, India

Re: Workers are grouped by their areas of expertise, and are [#permalink]
Show Tags
29 Apr 2014, 23:26
nandinigaur wrote: Hi
How to identify when the qs is meaning to say exactly 2 overlaps and when the qs means otherwise? This qs seemed like it meant exactly 2. The question will have words such as 'only' or 'exactly' when it wants to specify that n number of people are in exactly 2 teams. 10 people belong to A and B implies that there are 10 people who belong to both. Some of them could belong to another set C too but that information is not available. All we know is that 10 belong to both A and B.
_________________
Karishma Veritas Prep  GMAT Instructor My Blog
Get started with Veritas Prep GMAT On Demand for $199
Veritas Prep Reviews



Manager
Joined: 28 Apr 2014
Posts: 249

Re: Workers are grouped by their areas of expertise, and are [#permalink]
Show Tags
05 May 2014, 20:55
VeritasPrepKarishma wrote: nandinigaur wrote: Hi
How to identify when the qs is meaning to say exactly 2 overlaps and when the qs means otherwise? This qs seemed like it meant exactly 2. The question will have words such as 'only' or 'exactly' when it wants to specify that n number of people are in exactly 2 teams. 10 people belong to A and B implies that there are 10 people who belong to both. Some of them could belong to another set C too but that information is not available. All we know is that 10 belong to both A and B. Thanks Karishma .. This was confusing me as well.



Manager
Joined: 20 Oct 2013
Posts: 54

Re: Workers are grouped by their areas of expertise, and are [#permalink]
Show Tags
06 May 2014, 05:13
VeritasPrepKarishma wrote: nandinigaur wrote: Hi
How to identify when the qs is meaning to say exactly 2 overlaps and when the qs means otherwise? This qs seemed like it meant exactly 2. The question will have words such as 'only' or 'exactly' when it wants to specify that n number of people are in exactly 2 teams. 10 people belong to A and B implies that there are 10 people who belong to both. Some of them could belong to another set C too but that information is not available. All we know is that 10 belong to both A and B. Dear Karishma I thought i understood but then i saw the following qs: In a consumer survey, 85% of those surveyed liked at least one of three products: 1, 2, and 3. 50% of those asked liked product 1, 30% liked product 2, and 20% liked product 3. If 5% of the people in the survey liked all three of the products, what percentage of the survey participants liked more than one of the three products? in this how to know that we r being asked: people in exactly 2 grps + people in exactly 3 grps... no word is mentioned....
_________________
Hope to clear it this time!! GMAT 1: 540 Preparing again



Math Expert
Joined: 02 Sep 2009
Posts: 46167

Re: Workers are grouped by their areas of expertise, and are [#permalink]
Show Tags
06 May 2014, 08:39
nandinigaur wrote: VeritasPrepKarishma wrote: nandinigaur wrote: Hi
How to identify when the qs is meaning to say exactly 2 overlaps and when the qs means otherwise? This qs seemed like it meant exactly 2. The question will have words such as 'only' or 'exactly' when it wants to specify that n number of people are in exactly 2 teams. 10 people belong to A and B implies that there are 10 people who belong to both. Some of them could belong to another set C too but that information is not available. All we know is that 10 belong to both A and B. Dear Karishma I thought i understood but then i saw the following qs: In a consumer survey, 85% of those surveyed liked at least one of three products: 1, 2, and 3. 50% of those asked liked product 1, 30% liked product 2, and 20% liked product 3. If 5% of the people in the survey liked all three of the products, what percentage of the survey participants liked more than one of the three products? in this how to know that we r being asked: people in exactly 2 grps + people in exactly 3 grps... no word is mentioned.... This question is discussed here: inaconsumersurvey85ofthosesurveyedlikedatleast98018.htmlHope it helps.
_________________
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



Veritas Prep GMAT Instructor
Joined: 16 Oct 2010
Posts: 8100
Location: Pune, India

Re: Workers are grouped by their areas of expertise, and are [#permalink]
Show Tags
06 May 2014, 23:26
nandinigaur wrote: I thought i understood but then i saw the following qs:
In a consumer survey, 85% of those surveyed liked at least one of three products: 1, 2, and 3. 50% of those asked liked product 1, 30% liked product 2, and 20% liked product 3. If 5% of the people in the survey liked all three of the products, what percentage of the survey participants liked more than one of the three products?
in this how to know that we r being asked: people in exactly 2 grps + people in exactly 3 grps... no word is mentioned.... If the question wants to tell you the number of people who like 2 products but not all 3, it will say "30% people liked exactly two products." Or "52% people liked only one of these products" when it wants to tell you that 52% people liked just a single product and did not like other two products and so on... In this particular question, you are asked to find the number of people who liked more than one of the three products. This means you want the number of people who liked either 2 of the 3 products or all three products. So you are looking for "people in exactly 2 grps + people in exactly 3 grps". Note that you can calculate this in two ways: Method 1: people in exactly 2 grps + people in exactly 3 grps Method 2: people in 2 grps (including those in all three groups too)  2* people in 3 grps (because they have been counted 3 times while counting people in 2 groups) Check out this post for more on three overlapping sets: http://www.veritasprep.com/blog/2012/09 ... pingsets/
_________________
Karishma Veritas Prep  GMAT Instructor My Blog
Get started with Veritas Prep GMAT On Demand for $199
Veritas Prep Reviews



Manager
Joined: 28 Dec 2013
Posts: 68

Re: Workers are grouped by their areas of expertise, and are [#permalink]
Show Tags
25 Jun 2014, 10:16
[quote="Bunuel"]Workers are grouped by their areas of expertise, and are placed on at least one team. 20 are on the marketing team, 30 are on the Sales team, and 40 are on the Vision team. 5 workers are on both the Marketing and Sales teams, 6 workers are on both the Sales and Vision teams, 9 workers are on both the Marketing and Vision teams, and 4 workers are on all three teams. How many workers are there in total?
Translating: "are placed on at least one team": members of none =0; "20 are on the marketing team": M=20; "30 are on the Sales team": S=30; "40 are on the Vision team": V=40; "5 workers are on both the Marketing and Sales teams": MnS=5, note here that some from these 5 can be the members of Vision team as well, MnS is sections d an g on the diagram (assuming Marketing = A, Sales = B and Vision = C); "6 workers are on both the Sales and Vision teams": SnV=6 (the same as above sections f an g); "9 workers are on both the Marketing and Vision teams": MnV=9. "4 workers are on all three teams": MnSnV=4, section 4.
Question: Total=?
Applying first formula as we have intersections of two groups and not the number of only (exactly) 2 group members:
\(Total=M+S+V(MnS+MnV+SnV)+MnSnV+Neither=20+30+40(5+6+9)+4+0=74\).
Answer: 74.
Why are we adding (5+6+9) when the formula has subtraction in it : (sum of exactly 2  group overlaps) ?
Thanks



Math Expert
Joined: 02 Sep 2009
Posts: 46167

Re: Workers are grouped by their areas of expertise, and are [#permalink]
Show Tags
25 Jun 2014, 10:19
sagnik242 wrote: Bunuel wrote: Workers are grouped by their areas of expertise, and are placed on at least one team. 20 are on the marketing team, 30 are on the Sales team, and 40 are on the Vision team. 5 workers are on both the Marketing and Sales teams, 6 workers are on both the Sales and Vision teams, 9 workers are on both the Marketing and Vision teams, and 4 workers are on all three teams. How many workers are there in total?
Translating: "are placed on at least one team": members of none =0; "20 are on the marketing team": M=20; "30 are on the Sales team": S=30; "40 are on the Vision team": V=40; "5 workers are on both the Marketing and Sales teams": MnS=5, note here that some from these 5 can be the members of Vision team as well, MnS is sections d an g on the diagram (assuming Marketing = A, Sales = B and Vision = C); "6 workers are on both the Sales and Vision teams": SnV=6 (the same as above sections f an g); "9 workers are on both the Marketing and Vision teams": MnV=9. "4 workers are on all three teams": MnSnV=4, section 4.
Question: Total=?
Applying first formula as we have intersections of two groups and not the number of only (exactly) 2 group members:
\(Total=M+S+V(MnS+MnV+SnV)+MnSnV+Neither=20+30+40(5+6+9)+4+0=74\).
Answer: 74.
Why are we adding (5+6+9) when the formula has subtraction in it : (sum of exactly 2  group overlaps) ?
Thanks Because MnS+MnV+SnV gives 2group overlaps.
_________________
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: 22 Feb 2014
Posts: 27

Re: Workers are grouped by their areas of expertise, and are [#permalink]
Show Tags
09 Jul 2014, 08:58
Bunuel wrote: alexjoh89 wrote: I have a question. If the formula is:
Total = Group1 + Group2 + Group3  (sum of 2group overlaps)  2*(all three) + Neither
why is it then + 4 instead of 2*4? There are two formulas for 3 overlapping sets: \(Total = A + B + C  (sum \ of \ 2group \ overlaps) + (all \ three) + Neither\). \(Total = A + B + C  (sum \ of \ EXACTLY \ 2group \ overlaps)  2*(all \ three) + Neither\). For more check here: ADVANCED OVERLAPPING SETS PROBLEMSIf I use second formula answer comes different.. Am i making any mistake?? Please correct 20+30+40 (20) 2(4)+0 9028 = 62 pLEASE aDVICE...are these two formulas suppose to give same answer right???



Math Expert
Joined: 02 Sep 2009
Posts: 46167

Re: Workers are grouped by their areas of expertise, and are [#permalink]
Show Tags
09 Jul 2014, 09:03
GGMAT730 wrote: Bunuel wrote: alexjoh89 wrote: I have a question. If the formula is:
Total = Group1 + Group2 + Group3  (sum of 2group overlaps)  2*(all three) + Neither
why is it then + 4 instead of 2*4? There are two formulas for 3 overlapping sets: \(Total = A + B + C  (sum \ of \ 2group \ overlaps) + (all \ three) + Neither\). \(Total = A + B + C  (sum \ of \ EXACTLY \ 2group \ overlaps)  2*(all \ three) + Neither\). For more check here: ADVANCED OVERLAPPING SETS PROBLEMSIf I use second formula answer comes different.. Am i making any mistake?? Please correct 20+30+40 (20) 2(4)+0 9028 = 62 pLEASE aDVICE...are these two formulas suppose to give same answer right??? They DO give the same answer when applied properly. As I wrote in my post above: we are applying first formula as we have intersections of two groups and not the number of only (exactly) 2 group members. You should understand those formulas, know when to apply which and not simply memorize them.
_________________
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



Veritas Prep GMAT Instructor
Joined: 16 Oct 2010
Posts: 8100
Location: Pune, India

Re: Workers are grouped by their areas of expertise, and are [#permalink]
Show Tags
09 Jul 2014, 22:29
GGMAT760 wrote:
If I use second formula answer comes different.. Am i making any mistake?? Please correct
20+30+40 (20) 2(4)+0 9028 = 62
pLEASE aDVICE...are these two formulas suppose to give same answer right???
You should understand the concept of the two formulas. They will obviously give the same answer but the inputs they require are different. Bunuel has given two formulas: \(Total = A + B + C  (sum \ of \ 2group \ overlaps) + (all \ three) + Neither\). \(Total = A + B + C  (sum \ of \ EXACTLY \ 2group \ overlaps)  2*(all \ three) + Neither\). Note that inputs are different. In formula 1, you subtract sum of 2 group overlaps, it contains all three thrice and hence all three gets completely removed. So you put it back in. In formula 2, you subtract sum of exactly two groups and hence it contains no elements of all three. All three has been counted three times in A, B and C and hence you subtract it twice. You can usually solve these questions with venn diagrams if formulas confuse you. Check out this post for more on three overlapping sets: http://www.veritasprep.com/blog/2012/09 ... pingsets/
_________________
Karishma Veritas Prep  GMAT Instructor My Blog
Get started with Veritas Prep GMAT On Demand for $199
Veritas Prep Reviews



Intern
Joined: 13 Aug 2015
Posts: 1

Re: Workers are grouped by their areas of expertise, and are [#permalink]
Show Tags
21 Aug 2015, 00:27
Answer is 62. Solved by both equations:
Hi, for all that are confused as to why there are 2 different answers from the given 2 equations, There are two formulas for 3 overlapping sets: Total=A+B+C−(sum of 2−group overlaps)+(all three)+Neither.
Total=A+B+C−(sum of EXACTLY 2−group overlaps)−2∗(all three)+Neither
The answer is supposed to be 62 for both of them.
For 1st Equation, as it is a sum of 2 group overlaps, it will also include the common(all three) 4 part with it. Total=A+B+C−(sum of 2−group overlaps)+(all three)+Neither Total= 20+30+40((5+4)+(9+4)+(6+4))+4+0=62 =9032+4 =62 For 2nd Equation, as it is a sum of 2 Exactly group overlaps, it will not include the common 4 part with it.
Total=A+B+C−(sum of EXACTLY 2−group overlaps)−2∗(all three)+Neither =20+30+40(5+9+6)2*4+0 =90208 =62
I hope I am right, and I hope everyone got it.



Manager
Joined: 10 Jun 2015
Posts: 121

Re: Workers are grouped by their areas of expertise, and are [#permalink]
Show Tags
21 Aug 2015, 04:37
BarneyStinson wrote: Workers are grouped by their areas of expertise, and are placed on at least one team. 20 are on the marketing team, 30 are on the Sales team, and 40 are on the Vision team. 5 workers are on both the Marketing and Sales teams, 6 workers are on both the Sales and Vision teams, 9 workers are on both the Marketing and Vision teams, and 4 workers are on all three teams. How many workers are there in total? Use venn diagram for this problem. Just fill the number of workers in the 7 regions. since 4 workers are on all teams, the workers on both M and S but not V will be 54=1 the workers on both S and V but not on M =64=2 the workers on both M and V but not on S =94=5 M only is 20(1+4+5)=10 S only is 30(1+2+4)=23 V only is 40(2+4+5)=29 therefore, the total workers =4+1+2+5+10+23+29=74



Intern
Joined: 26 May 2014
Posts: 41
Location: India
Concentration: General Management, Technology
WE: Information Technology (Computer Software)

Re: Workers are grouped by their areas of expertise, and are [#permalink]
Show Tags
26 Jul 2016, 13:39
"20 are on the marketing team, 30 are on the Sales team, and 40 are on the Vision team"
How do we know 20 , 30 and 40 are not intersection values . For eg. if 20 were placed in marketing, 4 out of them could be in Sales also, so how did we assume M=20 ?Likewise for values of S and V



Veritas Prep GMAT Instructor
Joined: 16 Oct 2010
Posts: 8100
Location: Pune, India

Re: Workers are grouped by their areas of expertise, and are [#permalink]
Show Tags
26 Jul 2016, 22:27
devbond wrote: "20 are on the marketing team, 30 are on the Sales team, and 40 are on the Vision team"
How do we know 20 , 30 and 40 are not intersection values . For eg. if 20 were placed in marketing, 4 out of them could be in Sales also, so how did we assume M=20 ?Likewise for values of S and V M, S and V in the formula are values including intersections. "20 are on the marketing team, ... 5 workers are on both the Marketing and Sales teams" These 5 are a part of the 20. In this formula: \(Total = A + B + C (sum \ of \ 2 \ group \ overlaps) + (all \ three) + Neither\) A, B and C include intersections. They represent the whole set.
_________________
Karishma Veritas Prep  GMAT Instructor My Blog
Get started with Veritas Prep GMAT On Demand for $199
Veritas Prep Reviews



Intern
Joined: 26 May 2014
Posts: 41
Location: India
Concentration: General Management, Technology
WE: Information Technology (Computer Software)

Re: Workers are grouped by their areas of expertise, and are [#permalink]
Show Tags
27 Jul 2016, 07:29
ThankYou! . I overlooked that!



Intern
Joined: 29 Apr 2011
Posts: 42

Re: Workers are grouped by their areas of expertise and are plac [#permalink]
Show Tags
29 Jul 2016, 09:53
babusona wrote: Workers are grouped by their areas of expertise and are placed on at least one team. 20 workers are on team A, 30 are on team B, 40 are on team C. 5 workers are on both team A and B, 6 workers are on both the B and C teams, 9 workers are on both the C and A teams and 4 workers are on all 3 teams. How many workers are there in total?
A. 62 B. 78 C. 74 D. 66 E. 72 This is a tricky question as many time we miss this simple word called "only" 5 workers are on both team A and B or 5 workers are on both team A and B + only. The result will dramatically differ. If you infer with "only", then answer will be A. 62 which is the wrong answer. Simple formula to memorize = Total = A+B+C  (summation of 2 overlaps) + (3 overlaps) This leads to answer C)74 and the correct answer



BSchool Forum Moderator
Joined: 12 Aug 2015
Posts: 2642
GRE 1: 323 Q169 V154

Workers are grouped by their areas of expertise, and are placed on [#permalink]
Show Tags
29 Jul 2016, 11:57
Workers are grouped by their areas of expertise, and are placed on at least one team. 20 are on the marketing team, 30 are on the Sales team, and 40 are on the Vision team. 5 workers are on both the Marketing and Sales teams, 6 workers are on both the Sales and Vision teams, 9 workers are on both the Marketing and Vision teams, and 4 workers are on all three teams. How many workers are there in total? A)74 B)90 C)70 D)66 E)cannot be determined Note => This is a copy of workersaregroupedbytheirareasofexpertiseandare90246.html > I added the options To make it fruitful
_________________
MBA Financing: INDIAN PUBLIC BANKS vs PRODIGY FINANCE! Getting into HOLLYWOOD with an MBA! The MOST AFFORDABLE MBA programs!STONECOLD's BRUTAL Mock Tests for GMATQuant(700+)AVERAGE GRE Scores At The Top Business Schools!




Workers are grouped by their areas of expertise, and are placed on
[#permalink]
29 Jul 2016, 11:57



Go to page
Previous
1 2 3
Next
[ 45 posts ]



