Find all School-related info fast with the new School-Specific MBA Forum

It is currently 22 Jul 2014, 22:24

Close

GMAT Club Daily Prep

Thank you for using the timer - this advanced tool can estimate your performance and suggest more practice questions. We have subscribed you to Daily Prep Questions via email.

Customized
for You

we will pick new questions that match your level based on your Timer History

Track
Your Progress

every week, we’ll send you an estimated GMAT score based on your performance

Practice
Pays

we will pick new questions that match your level based on your Timer History

Not interested in getting valuable practice questions and articles delivered to your email? No problem, unsubscribe here.

Events & Promotions

Events & Promotions in June
Open Detailed Calendar

A contractor combined x tons of a gravel mixture that

  Question banks Downloads My Bookmarks Reviews Important topics  
Author Message
TAGS:
2 KUDOS received
Director
Director
avatar
Joined: 01 Aug 2008
Posts: 770
Followers: 3

Kudos [?]: 74 [2] , given: 99

GMAT Tests User
A contractor combined x tons of a gravel mixture that [#permalink] New post 28 Jan 2010, 14:07
2
This post received
KUDOS
3
This post was
BOOKMARKED
00:00
A
B
C
D
E

Difficulty:

  45% (medium)

Question Stats:

50% (01:42) correct 50% (00:48) wrong based on 284 sessions
A contractor combined x tons of a gravel mixture that contained 10 percent gravel G, by weight, with y tons of a mixture that contained 2 percent gravel G, by weight, to produce z tons of a mixture that was 5 percent gravel G, by weight. What is the value of x ?

(1) y = 10

(2) z = 16
[Reveal] Spoiler: OA

Last edited by Bunuel on 31 Mar 2012, 11:02, edited 1 time in total.
Edited the question
Expert Post
12 KUDOS received
Math Expert
User avatar
Joined: 02 Sep 2009
Posts: 18683
Followers: 3232

Kudos [?]: 22223 [12] , given: 2601

Re: x tons of a gravel mixture [#permalink] New post 28 Jan 2010, 15:25
12
This post received
KUDOS
Expert's post
ugimba wrote:
119.A contractor combined x tons of a gravel mixture that contained 10 percent gravel G, by weight, with y tons of a mixture that contained 2 percent gravel G, by weight, to produce z tons of a mixture that was 5 percent gravel G, by weight. What is the value of x ?

(1) y = 10

(2) z = 16


Set the equation: 0.1x+0.02y=0.05(x+y), where x+y=z --> 5x=3y --> Q: x=?

(1) y=10 --> 5x=3y=30 --> x=6. Sufficient.

(2) z=x+y=16 --> y=16-x --> 5x=3y=3(16-x) --> x=6. 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; 11. GMAT Prep Software Analysis NEW!!!; 12. SEVEN SAMURAI OF 2012 (BEST DISCUSSIONS) NEW!!!; 12. Tricky questions from previous years. NEW!!!;

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?
25 extra-hard Quant Tests

Get the best GMAT Prep Resources with GMAT Club Premium Membership

1 KUDOS received
Manager
Manager
avatar
Joined: 03 May 2010
Posts: 89
WE 1: 2 yrs - Oilfield Service
Followers: 11

Kudos [?]: 57 [1] , given: 7

GMAT Tests User Reviews Badge
Re: gmat prep DS [#permalink] New post 15 Jun 2010, 04:53
1
This post received
KUDOS
What does the prompt tell us?

x + y = z

0.1x + 0.02y = 0.05z

We have to find x. If you notice, we have two equations in 3 variables, so if we are given a value for either y OR z, this is sufficient to calculate x.

1. Gives us y. Sufficient.

2. Gives us Z. Sufficient.

Pick D.
Intern
Intern
User avatar
Affiliations: NYSSA
Joined: 07 Jun 2010
Posts: 35
Location: New York City
Schools: Wharton, Stanford, MIT, NYU, Columbia, LBS, Berkeley (MFE program)
WE 1: Senior Associate - Thomson Reuters
WE 2: Analyst - TIAA CREF
Followers: 0

Kudos [?]: 4 [0], given: 2

Re: x tons of a gravel mixture [#permalink] New post 15 Jun 2010, 11:19
Goofed on this and answered B too quickly.

D it is...

we have .01x+.02y=.05z & x+y=z

1) y=10 means -> z-x=10, plug the numbers.
2) z=16 means -> x+y=16, plug the numbers
Manager
Manager
avatar
Joined: 20 Mar 2010
Posts: 84
Followers: 2

Kudos [?]: 46 [0], given: 1

Re: Gravel Mixture [#permalink] New post 15 Aug 2010, 23:34
lalithajob wrote:
A contractor combined x tons of a gravel mixture that contained 10% gravel G, by weight, with y tons of a mixture that contained 2% gravel G, by weight, to produce z tons of a mixture that was 5% gravel G, by weight. What is the value of x?

1. y = 10
2. z = 16


x + y = z ( x tons of mixture1 + y tons of mixture2 = z tons of combined mixture)
.1x + .02y = .05z (gravel in mixture1 + gravel in mixture2 = gravel in combined mixture)

x= ?

1) y=10. 3 equations(2 from the question + 1 from answer choice) with 3 unknowns. Can solve for x. Sufficient
2) z=16. 3 equations(2 from the question + 1 from answer choice) with 3 unknowns. Can solve for x. Sufficient

Answer D

_________________

___________________________________
Please give me kudos if you like my post

Manager
Manager
avatar
Joined: 16 Apr 2010
Posts: 223
Followers: 3

Kudos [?]: 40 [0], given: 12

GMAT Tests User
Re: Gravel Mixture [#permalink] New post 15 Aug 2010, 23:35
Hello,

From above we have:
0.1x + 0.02y = 0.05z
x+y = z
Thus,
0.1x + 0.02y = 0.05(x+y)
0.05x=0.03y
5x=3y

Statement 1
y=10 thus x =6 sufficient

Statement 2
z=16=x+y
and we have 5x=3y
Thus we have 2 equations with 2 unknowns; we can find x. Again sufficient.
Intern
Intern
avatar
Joined: 24 Jun 2010
Posts: 41
Location: Toronto
Schools: Berkeley Haas, UCLA Anderson, NYU Stern
Followers: 1

Kudos [?]: 5 [0], given: 3

Re: x tons of a gravel mixture [#permalink] New post 17 Aug 2010, 12:05
Question:
For these types of questions can you always do
Z=X+Y?

This is the first question that I've seen like this.
I'm not sure if I would have gone with Z=X+Y, as Z could have been the combination X+Y and some other non-gravel material
Intern
Intern
avatar
Joined: 03 Sep 2010
Posts: 17
Followers: 0

Kudos [?]: 4 [0], given: 0

GMAT Tests User
Re: mixture problem [#permalink] New post 11 Oct 2010, 21:35
The answer in my opinion should be D)

By condition ,

10% X + 2% Y = 5 % Z ---(1)
Also X + Y = Z ---(2)

Option (A) is sufficient to get the value of X by substituting the value of Y = 10
Option (B) is sufficient to get the value of X by substituting the value of Z = 16
Expert Post
3 KUDOS received
Veritas Prep GMAT Instructor
User avatar
Joined: 16 Oct 2010
Posts: 4564
Location: Pune, India
Followers: 1029

Kudos [?]: 4453 [3] , given: 162

Re: a contractor combined x tons ofa gravel mixture [#permalink] New post 26 Dec 2010, 22:06
3
This post received
KUDOS
Expert's post
anilnandyala wrote:
a contractor combined x tons ofa gravel mixture that contained 10% gravel g by weight with y tons of a mixture that contained 2% gravel g by weight to produce z tons of a mixture that was 5% gravel by weight. what is the value of x?

y = 10
z = 16


Using scale method here, since 10% and 2% give weighted average of 5%, x:y = 3:5
We also know x + y = z.

1. y = 10.
If y = 10, x = 6 since their ratios must be 3:5. Sufficient.

2. z = 16
If sum of x and y is 16, x must be 6 and y must be 10 to give a ratio of 3:5.

If this is not intuitive, think of it this way:
x : y...... x + y
3 : 5...... 8
Since 8 in ratio terms is actually 16, 3 is actually 6 and 5 is actually 10.

Answer (D)

It will be worth your while if you understand the scale method. The time saving is huge and weighted average is a concept you will need to use time and again. For explanation of scale method, check this link:
http://gmatclub.com/forum/tough-ds-105651.html#p828579

_________________

Karishma
Veritas Prep | GMAT Instructor
My Blog

Save $100 on Veritas Prep GMAT Courses And Admissions Consulting
Enroll now. Pay later. Take advantage of Veritas Prep's flexible payment plan options.

Veritas Prep Reviews

Manager
Manager
User avatar
Joined: 19 Dec 2010
Posts: 145
Followers: 2

Kudos [?]: 16 [0], given: 12

GMAT Tests User
new [#permalink] New post 12 Mar 2011, 22:38
The answer is D.
I was flummoxed on this one since at first I thought it was C, then I looked at it closer and thought it was B. Now I see how A and B are sufficient.
Crazy DS - I HATE YOU!
Manager
Manager
User avatar
Joined: 19 Dec 2010
Posts: 145
Followers: 2

Kudos [?]: 16 [0], given: 12

GMAT Tests User
Re: GMAT Prep DS- Mixture problem [#permalink] New post 12 Mar 2011, 22:41
Easy way to solve this problem:
X lbs + Y lbs = Z lbs

Given 10% X + 2% Y = 5% Z
1) Y=10
2 eqns, 2 unknowns, solve!

2)Z= given.
Same as above, solve
Director
Director
User avatar
Status: GMAT Learner
Joined: 14 Jul 2010
Posts: 653
Followers: 32

Kudos [?]: 191 [0], given: 32

GMAT Tests User
Re: mixture problem [#permalink] New post 13 Mar 2011, 10:38
0.1x+0.02y=0.05(x+y)
1. suff.
2. x+y=16
y=16-x suf..

d ans

_________________

I am student of everyone-baten
Collections:-
PSof OG solved by GC members: http://gmatclub.com/forum/collection-ps-with-solution-from-gmatclub-110005.html
DS of OG solved by GC members: http://gmatclub.com/forum/collection-ds-with-solution-from-gmatclub-110004.html
100 GMAT PREP Quantitative collection http://gmatclub.com/forum/gmat-prep-problem-collections-114358.html
Collections of work/rate problems with solutions http://gmatclub.com/forum/collections-of-work-rate-problem-with-solutions-118919.html
Mixture problems in a file with best solutions: http://gmatclub.com/forum/mixture-problems-with-best-and-easy-solutions-all-together-124644.html

Manager
Manager
User avatar
Joined: 26 Jul 2010
Posts: 101
Location: India
Concentration: Operations, General Management
Schools: IIMA
GMAT 1: 640 Q48 V29
GMAT 2: 670 Q49 V31
WE: Supply Chain Management (Military & Defense)
Followers: 4

Kudos [?]: 14 [0], given: 5

CAT Tests
Re: mixture problem [#permalink] New post 22 Apr 2011, 23:09
remember X+Y=Z in que statement

if you will not notice this statement you will land up to another answer

_________________

lets start again

Manager
Manager
avatar
Joined: 11 Dec 2010
Posts: 115
WE: Consulting (Consulting)
Followers: 4

Kudos [?]: 23 [0], given: 50

Re: mixture problem [#permalink] New post 23 Apr 2011, 07:51
Using the method of alligations,
10:2
5
3:5
The quantities of x and y = x:y=3:5
z=8
So any one of the variables y and z will give the variable x

So answer is D
Intern
Intern
avatar
Joined: 31 Mar 2012
Posts: 2
Followers: 0

Kudos [?]: 0 [0], given: 6

Re: A contractor combined x tons of a gravel mixture that [#permalink] New post 15 Apr 2012, 15:37
Can anyone please explain on X+Y=Z in que statement. I definitely missed it and ended up with answer C
Where in question it says that x+y=z?
Expert Post
Math Expert
User avatar
Joined: 02 Sep 2009
Posts: 18683
Followers: 3232

Kudos [?]: 22223 [0], given: 2601

Re: A contractor combined x tons of a gravel mixture that [#permalink] New post 15 Apr 2012, 15:40
Expert's post
ad20 wrote:
Can anyone please explain on X+Y=Z in que statement. I definitely missed it and ended up with answer C
Where in question it says that x+y=z?


Sure. Question says: "A contractor combined x tons of a gravel mixture that contained 10 percent gravel G, by weight, with y tons of a mixture that contained 2 percent gravel G, by weight, to produce z tons of a mixture."

Hope it's clear.

_________________

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; 11. GMAT Prep Software Analysis NEW!!!; 12. SEVEN SAMURAI OF 2012 (BEST DISCUSSIONS) NEW!!!; 12. Tricky questions from previous years. NEW!!!;

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?
25 extra-hard Quant Tests

Get the best GMAT Prep Resources with GMAT Club Premium Membership

Expert Post
Math Expert
User avatar
Joined: 02 Sep 2009
Posts: 18683
Followers: 3232

Kudos [?]: 22223 [0], given: 2601

Re: A contractor combined x tons of a gravel mixture that [#permalink] New post 13 Jun 2013, 01:15
Expert's post
Bumping for review and further discussion*. Get a kudos point for an alternative solution!

*New project from GMAT Club!!! Check HERE

All DS Mixture Problems to practice: search.php?search_id=tag&tag_id=43
All PS Mixture Problems to practice: search.php?search_id=tag&tag_id=114

_________________

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; 11. GMAT Prep Software Analysis NEW!!!; 12. SEVEN SAMURAI OF 2012 (BEST DISCUSSIONS) NEW!!!; 12. Tricky questions from previous years. NEW!!!;

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?
25 extra-hard Quant Tests

Get the best GMAT Prep Resources with GMAT Club Premium Membership

Intern
Intern
avatar
Joined: 04 Aug 2013
Posts: 3
Followers: 0

Kudos [?]: 0 [0], given: 1

Premium Member
GMAT prep Q [#permalink] New post 09 May 2014, 04:55
A contractor combined x tons of a gravel mixture that contained 10 percent G, by weight ,with y tons of a mixture that contained 2 percent gravel G ,by weight,to produce z tons of a mixture that was 5 percent gravel G by weight.What is the value of x?
1) y=10
2) z=16
1 KUDOS received
Intern
Intern
User avatar
Status: Learning
Joined: 07 Aug 2011
Posts: 27
Location: India
Schools: WBUT - Class of 2011
GMAT Date: 01-06-2014
GPA: 2.6
WE: Research (Education)
Followers: 0

Kudos [?]: 4 [1] , given: 6

CAT Tests
Re: GMAT prep Q [#permalink] New post 09 May 2014, 05:02
1
This post received
KUDOS
Set the equation: 0.1x+0.02y=0.05(x+y), where x+y=z --> 5x=3y --> Q: x=?

(1) y=10 --> 5x=3y=30 --> x=6. Sufficient.

(2) z=x+y=16 --> y=16-x --> 5x=3y=3(16-x) --> x=6. Sufficient.

Answer: D.

_________________

If you like my post give me kudos.

Arindam Sur
Researcher, Academian

Expert Post
1 KUDOS received
Math Expert
User avatar
Joined: 02 Sep 2009
Posts: 18683
Followers: 3232

Kudos [?]: 22223 [1] , given: 2601

Re: GMAT prep Q [#permalink] New post 09 May 2014, 05:54
1
This post received
KUDOS
Expert's post
vikasogs wrote:
A contractor combined x tons of a gravel mixture that contained 10 percent G, by weight ,with y tons of a mixture that contained 2 percent gravel G ,by weight,to produce z tons of a mixture that was 5 percent gravel G by weight.What is the value of x?
1) y=10
2) z=16


Merging similar topics. Please refer to the discussion above.

Also, please read carefully and follow: rules-for-posting-please-read-this-before-posting-133935.html Pay attention to rules 1 and 3. 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; 11. GMAT Prep Software Analysis NEW!!!; 12. SEVEN SAMURAI OF 2012 (BEST DISCUSSIONS) NEW!!!; 12. Tricky questions from previous years. NEW!!!;

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?
25 extra-hard Quant Tests

Get the best GMAT Prep Resources with GMAT Club Premium Membership

Re: GMAT prep Q   [#permalink] 09 May 2014, 05:54
    Similar topics Author Replies Last post
Similar
Topics:
A contractor combined "x" tons of a gravel mixture that gmat9003 3 24 May 2011, 18:38
A contractor combined x tons of a gravel mixture that Ibodullo 3 02 Sep 2009, 01:50
2 A contractor combined x tons of gravel mixture that cotained GMATBLACKBELT 9 17 Oct 2007, 18:39
1 Experts publish their posts in the topic A contractor combined x tons of a gravel mixture that contai bewakoof 9 09 Apr 2006, 15:49
A contractor combined x tons of a gravel mixture that remgeo 7 21 Mar 2006, 08:54
Display posts from previous: Sort by

A contractor combined x tons of a gravel mixture that

  Question banks Downloads My Bookmarks Reviews Important topics  


GMAT Club MBA Forum Home| About| Privacy Policy| Terms and Conditions| GMAT Club Rules| Contact| Sitemap

Powered by phpBB © phpBB Group and phpBB SEO

Kindly note that the GMAT® test is a registered trademark of the Graduate Management Admission Council®, and this site has neither been reviewed nor endorsed by GMAC®.