Check GMAT Club Decision Tracker for the Latest School Decision Releases https://gmatclub.com/AppTrack

 It is currently 26 May 2017, 21:56

### 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

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

# Events & Promotions

###### Events & Promotions in June
Open Detailed Calendar

# A contractor combined x tons of gravel mixture that cotained

Author Message
TAGS:

### Hide Tags

CEO
Joined: 29 Mar 2007
Posts: 2562
Followers: 21

Kudos [?]: 453 [0], given: 0

A contractor combined x tons of gravel mixture that cotained [#permalink]

### Show Tags

17 Oct 2007, 19:39
6
This post was
BOOKMARKED
00:00

Difficulty:

(N/A)

Question Stats:

67% (01:55) correct 33% (00:46) wrong based on 135 sessions

### HideShow timer Statistics

A contractor combined x tons of gravel mixture that cotained 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 misture that was 5 percent gravel G,
by weight. What is the value of X?

1) y=10
2) z=16

TOPIC LOCKED. REFER TO a-contractor-combined-x-tons-of-a-gravel-mixture-that-102681.html FOR OPEN DISCUSSION OF THE TOPIC.
CEO
Joined: 29 Mar 2007
Posts: 2562
Followers: 21

Kudos [?]: 453 [0], given: 0

Re: A contractor combined x tons of gravel mixture that cotained [#permalink]

### Show Tags

17 Oct 2007, 19:41
Here is what i wrote down, but I don't think its the right way to do this. I really bad at mixture probs.

x+y=z

.10x+.02y=.05z

Knowng the value of X,Y, or Z, we can solve for any of the variables this problem given the equations above.

I get D this way, but again i dunno if its just coincidence.
Senior Manager
Joined: 28 Jun 2007
Posts: 317
Followers: 1

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

Re: A contractor combined x tons of gravel mixture that cotained [#permalink]

### Show Tags

18 Oct 2007, 09:35
Your approach looks right to me.

This note is for Killersquirrel....

Killersquirrel, can you solve this problem using your approach? I could not solve it that way.
Manager
Joined: 02 Feb 2007
Posts: 118
Followers: 1

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

Re: A contractor combined x tons of gravel mixture that cotained [#permalink]

### Show Tags

18 Oct 2007, 12:01
hey guys, i got D also, but my approach was a bit different, call it old fashion if you'd like.

I figured from the problem that x=10% gravel (G) y=2%G, and Z=5%G
we know that z=x+y

if we know x=10, therefore 10=10%G, so we find out how much gravel is in the mixture. After we find G, z=5%G, and it proves suff. Same goes for y, also suff, becasue we can find the gravel from it.

VP
Joined: 08 Jun 2005
Posts: 1145
Followers: 7

Kudos [?]: 213 [2] , given: 0

Re: A contractor combined x tons of gravel mixture that cotained [#permalink]

### Show Tags

18 Oct 2007, 13:35
2
KUDOS
see attachment:

The new ratio is 3:5

statement 1

when you know that Y=10 then

10/X = 5/3

30 = 5X

6 = X

sufficient

statement 2

since Z = 16 and you know that 16/(5+3) = 2 then X=3*2 Y=5*2

sufficient

Attachments

untitled.JPG [ 7.19 KiB | Viewed 5461 times ]

Intern
Joined: 18 Sep 2007
Posts: 8
Followers: 0

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

Re: A contractor combined x tons of gravel mixture that cotained [#permalink]

### Show Tags

18 Oct 2007, 15:41
KillerSquirrel wrote:
see attachment:

The new ratio is 3:5

statement 1

when you know that Y=10 then

10/X = 5/3

30 = 5X

6 = X

sufficient

statement 2

since Z = 16 and you know that 16/(5+3) = 2 then X=3*2 Y=5*2

sufficient

Hey, KS...would you mind explaining this a little further?

Thanks!
GMAT Club Legend
Joined: 07 Jul 2004
Posts: 5045
Location: Singapore
Followers: 31

Kudos [?]: 376 [0], given: 0

Re: A contractor combined x tons of gravel mixture that cotained [#permalink]

### Show Tags

18 Oct 2007, 18:37
z/20 = x/10 + y/50
5z = 10x + 2y
Since z = x+y,
5x + 5y = 10x+2y
x = 3y/5

St1:
y = 10. Sufficient. Can solve for x.

St2:
z = 16.

5z = 10x+2y
80 = 10x + 2y

Possible sets:
x = 7, y = 5 (x+y = 12. Out)
x = 6, y = 10 (x+y = 16. In)
x = 5, y = 15 (x+y = 20. Out)
x = 4, y = 20 (x+y = 24. Out)
x = 3, y = 25 (x+y = 28. Out)
....

So only one set works, x = 6, y = 10. Sufficient.

Ans D
Director
Joined: 25 Oct 2008
Posts: 601
Location: Kolkata,India
Followers: 15

Kudos [?]: 902 [0], given: 100

Re: A contractor combined x tons of gravel mixture that cotained [#permalink]

### Show Tags

15 Aug 2009, 20:04
I was lost without you ywilfred !!
_________________

http://gmatclub.com/forum/countdown-beginshas-ended-85483-40.html#p649902

Manager
Joined: 08 Oct 2009
Posts: 64
Location: Denver, CO
WE 1: IT Business Analyst-Building Materials Industry
Followers: 1

Kudos [?]: 20 [0], given: 4

Re: A contractor combined x tons of gravel mixture that cotained [#permalink]

### Show Tags

17 Feb 2010, 17:57
I have to give kudos to Killer Squirrel for posting his approach. I am not a math person so the algebraic method makes no sense to me. KS's approach is helping me destroy these problems. Just one questing is there any limitations to this approach?
Manager
Joined: 26 Jul 2010
Posts: 103
Location: India
Concentration: Operations, General Management
Schools: IIMA (M)
GMAT 1: 640 Q48 V29
GMAT 2: 670 Q49 V31
WE: Supply Chain Management (Military & Defense)
Followers: 6

Kudos [?]: 27 [0], given: 6

Re: A contractor combined x tons of gravel mixture that cotained [#permalink]

### Show Tags

22 Apr 2011, 23:51

there is a similar question on forum in mixture prob
_________________

lets start again

GMAT Club Legend
Joined: 09 Sep 2013
Posts: 15472
Followers: 649

Kudos [?]: 209 [0], given: 0

Re: A contractor combined x tons of gravel mixture that cotained [#permalink]

### Show Tags

05 Jan 2016, 13:58
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.
_________________
Re: A contractor combined x tons of gravel mixture that cotained   [#permalink] 05 Jan 2016, 13:58
Similar topics Replies Last post
Similar
Topics:
2 X and Y are both positive integers whose combined factors include 3 an 5 27 Apr 2017, 19:03
6 Solution X, which is 10% alcohol is combined 2 30 Sep 2016, 10:42
A contractor combined "x" tons of a gravel mixture that 3 14 Dec 2011, 11:40
113 A contractor combined x tons of a gravel mixture that 27 28 Jan 2017, 15:44
2 A contractor combined x tons of a gravel mixture that contained 10 per 5 25 Aug 2015, 23:44
Display posts from previous: Sort by