|
Author |
Message |
|
TAGS:
|
|
|
GMAT Club team member
Joined: 02 Sep 2009
Posts: 12116
Followers: 1879
Kudos [?]:
10129
[0], given: 965
|
In a random sample of 80 adults, how many are college [#permalink]
 18 Sep 2012, 03:28
Question Stats:
78% (01:39) correct
21% (00:17) wrong based on 33 sessions
The Official Guide for GMAT® Review, 13th Edition - Quantitative Questions ProjectIn a random sample of 80 adults, how many are college graduates? (1) In the sample, the number of adults who are not college graduates is 3 times the number who are college graduates. (2) In the sample, the number of adults who are not college graduates is 40 more than the number who are college graduates. Practice Questions
Question: 44
Page: 278
Difficulty: 600 GMAT Club is introducing a new project: The Official Guide for GMAT® Review, 13th Edition - Quantitative Questions ProjectEach week we'll be posting several questions from The Official Guide for GMAT® Review, 13th Edition and then after couple of days we'll provide Official Answer (OA) to them along with a slution. We'll be glad if you participate in development of this project: 1. Please provide your solutions to the questions; 2. Please vote for the best solutions by pressing Kudos button; 3. Please vote for the questions themselves by pressing Kudos button; 4. Please share your views on difficulty level of the questions, so that we have most precise evaluation. Thank you! _________________
NEW TO MATH FORUM? PLEASE READ THIS: ALL YOU NEED FOR QUANT!!!
PLEASE READ AND FOLLOW: 11 Rules for Posting!!!
RESOURCES: [GMAT MATH BOOK]; 1. Triangles; 2. Polygons; 3. Coordinate Geometry; 4. Factorials; 5. Circles; 6. Number Theory; 7. Remainders; 8. Overlapping Sets; 9. PDF of Math Book; 10. Remainders
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. NEW!!! ,11 Mixed Questions NEW!!!, 12 Fresh Meat NEW!!!
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. NEW!!!, 11 New DS set. NEW!!!
What are GMAT Club Tests?
25 extra-hard Quant Tests
Find out what's new at GMAT Club - latest features and updates
|
|
|
|
|
|
|
|
|
GMAT Club team member
Joined: 02 Sep 2009
Posts: 12116
Followers: 1879
Kudos [?]:
10129
[0], given: 965
|
Re: In a random sample of 80 adults, how many are college [#permalink]
18 Sep 2012, 03:29
SOLUTIONIn a random sample of 80 adults, how many are college graduates?(1) In the sample, the number of adults who are not college graduates is 3 times the number who are college graduates. Say the number of college graduates is x, then the number of not college graduates is 3x. Thus, x+3x=80. We can find x. Sufficient. (2) In the sample, the number of adults who are not college graduates is 40 more than the number who are college graduates. Say the number of college graduates is x, then the number of not college graduates is x+(x+40). Thus, x+(x+40)=80. We can find x. Sufficient. Answer: D.
_________________
NEW TO MATH FORUM? PLEASE READ THIS: ALL YOU NEED FOR QUANT!!!
PLEASE READ AND FOLLOW: 11 Rules for Posting!!!
RESOURCES: [GMAT MATH BOOK]; 1. Triangles; 2. Polygons; 3. Coordinate Geometry; 4. Factorials; 5. Circles; 6. Number Theory; 7. Remainders; 8. Overlapping Sets; 9. PDF of Math Book; 10. Remainders
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. NEW!!! ,11 Mixed Questions NEW!!!, 12 Fresh Meat NEW!!!
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. NEW!!!, 11 New DS set. NEW!!!
What are GMAT Club Tests?
25 extra-hard Quant Tests
Find out what's new at GMAT Club - latest features and updates
|
|
|
|
|
|
Senior Manager
Joined: 24 Aug 2009
Posts: 312
Schools: Harvard, Columbia, Stern, Booth, LSB,
Followers: 2
Kudos [?]:
159
[1] , given: 229
|
Re: In a random sample of 80 adults, how many are college [#permalink]
18 Sep 2012, 05:14
1
This post received
KUDOS
Let the number of adults who are college graduates = x & number of adults who are not college graduates = y x+y = 80 ...(1) 1) y = 3x Putting in equation (1), we get 4x= 80-----Sufficient 2) y = x + 40 Putting in equation (1), we get 2x + 40= 80-----Sufficient Answer D
_________________
If you like my Question/Explanation or the contribution, Kindly appreciate by pressing KUDOS.
Kudos always maximizes GMATCLUB worth -Game Theory
|
|
|
|
|
|
Manager
Joined: 12 Mar 2012
Posts: 171
Location: India
Concentration: Technology, General Management
GMAT Date: 07-23-2012
WE: Programming (Telecommunications)
Followers: 0
Kudos [?]:
26
[0], given: 4
|
Re: In a random sample of 80 adults, how many are college [#permalink]
18 Sep 2012, 06:39
Bunuel wrote:
In a random sample of 80 adults, how many are college graduates?
(1) In the sample, the number of adults who are not college graduates is 3 times the number who are college graduates.
(2) In the sample, the number of adults who are not college graduates is 40 more than the number who are college graduates.
Since there are 80 adults we don't need to consider non-adults number here. Otherwise, we would have to solve this by 2X2 matrix. Either adults are college graduates (X) or not (Y) Stmt 1) X + Y = 80 Y = 3X these 2 eq can be solved to get the value of X Stmt 2) Similar way X + Y = 80 Y = 40 + X these 2 eqns can also be solved for value of X Both statements are sufficient, Hence D
_________________
FOCUS..this is all I need!
Ku-Do!
|
|
|
|
|
|
Manager
Joined: 02 Jun 2011
Posts: 115
Followers: 0
Kudos [?]:
18
[0], given: 5
|
Re: In a random sample of 80 adults, how many are college [#permalink]
18 Sep 2012, 10:18
Bunuel wrote: The Official Guide for GMAT® Review, 13th Edition - Quantitative Questions ProjectIn a random sample of 80 adults, how many are college graduates? (1) In the sample, the number of adults who are not college graduates is 3 times the number who are college graduates. (2) In the sample, the number of adults who are not college graduates is 40 more than the number who are college graduates. Practice Questions
Question: 44
Page: 278
Difficulty: 600 GMAT Club is introducing a new project: The Official Guide for GMAT® Review, 13th Edition - Quantitative Questions ProjectEach week we'll be posting several questions from The Official Guide for GMAT® Review, 13th Edition and then after couple of days we'll provide Official Answer (OA) to them along with a slution. We'll be glad if you participate in development of this project: 1. Please provide your solutions to the questions; 2. Please vote for the best solutions by pressing Kudos button; 3. Please vote for the questions themselves by pressing Kudos button; 4. Please share your views on difficulty level of the questions, so that we have most precise evaluation. Thank you! Lets say college going graduate is X and college not going graduate is Y form question X + Y = 80. Option 1: Y = 3X so, X + 3X = 80 leads to X = 20. Therefore option 1 is sufficient to answer the question. Option 2: Y - X = 40. so, 2Y = 120, leads to Y = 60 and X = 20. therefore option 2 is sufficient to anser the question. Therefor from above both the options are individually sufficient to answer the question => "D" is the correct choice.
|
|
|
|
|
|
Senior Manager
Joined: 13 Aug 2012
Posts: 468
Followers: 13
Kudos [?]:
88
[1] , given: 11
|
Re: In a random sample of 80 adults, how many are college [#permalink]
20 Sep 2012, 00:30
1
This post received
KUDOS
Total of 80 adults.
Let C be the college graduates.
let N be the non college grads.
What is C?
(1) N = 3C
3C + C = 80, SUFFICIENT.
(2) N = 40 + C
40 + C + C = 80, SUFFICIENT
answer: D
|
|
|
|
|
|
GMAT Club team member
Joined: 02 Sep 2009
Posts: 12116
Followers: 1879
Kudos [?]:
10129
[0], given: 965
|
Re: In a random sample of 80 adults, how many are college [#permalink]
21 Sep 2012, 04:10
SOLUTIONIn a random sample of 80 adults, how many are college graduates?(1) In the sample, the number of adults who are not college graduates is 3 times the number who are college graduates. Say the number of college graduates is x, then the number of not college graduates is 3x. Thus, x+3x=80. We can find x. Sufficient. (2) In the sample, the number of adults who are not college graduates is 40 more than the number who are college graduates. Say the number of college graduates is x, then the number of not college graduates is x+(x+40). Thus, x+(x+40)=80. We can find x. Sufficient. Answer: D. Kudos points given to everyone with correct solution. Let me know if I missed someone.
_________________
NEW TO MATH FORUM? PLEASE READ THIS: ALL YOU NEED FOR QUANT!!!
PLEASE READ AND FOLLOW: 11 Rules for Posting!!!
RESOURCES: [GMAT MATH BOOK]; 1. Triangles; 2. Polygons; 3. Coordinate Geometry; 4. Factorials; 5. Circles; 6. Number Theory; 7. Remainders; 8. Overlapping Sets; 9. PDF of Math Book; 10. Remainders
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. NEW!!! ,11 Mixed Questions NEW!!!, 12 Fresh Meat NEW!!!
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. NEW!!!, 11 New DS set. NEW!!!
What are GMAT Club Tests?
25 extra-hard Quant Tests
Find out what's new at GMAT Club - latest features and updates
|
|
|
|
|
|
|
Re: In a random sample of 80 adults, how many are college
[#permalink]
21 Sep 2012, 04:10
|
|
|
|
|
|
|
|
|
|
|
close
