It is currently 18 Nov 2017, 22:09

### 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

# Seed mixture X is 40 percent ryegrass and 60 percent

Author Message
TAGS:

### Hide Tags

SVP
Joined: 04 May 2006
Posts: 1878

Kudos [?]: 1443 [7], given: 1

Schools: CBS, Kellogg
Seed mixture X is 40 percent ryegrass and 60 percent [#permalink]

### Show Tags

26 Feb 2008, 19:46
7
KUDOS
92
This post was
BOOKMARKED
00:00

Difficulty:

45% (medium)

Question Stats:

72% (01:29) correct 28% (01:55) wrong based on 2041 sessions

### HideShow timer Statistics

Seed mixture X is 40 percent ryegrass and 60 percent bluegrass by weight; seed mixture Y is 25 percent ryegrass and 75 % fescue. If a mixture of X and Y contains 30% ryegrass, what percent of the weight of the mixture is X?

A. 10%
B. 33 1/3%
C. 40%
D. 50%
E. 66 2/3%
[Reveal] Spoiler: OA

_________________

Kudos [?]: 1443 [7], given: 1

SVP
Joined: 29 Aug 2007
Posts: 2471

Kudos [?]: 855 [8], given: 19

### Show Tags

27 Feb 2008, 01:41
8
KUDOS
5
This post was
BOOKMARKED
sondenso wrote:
240. Seed mixture X is 40 percent ryegrass and 60 percent bluegrass by weight; seed mixture Y is 25 percent ryegrass and 75 % fescue. If a mixture of X and Y contains 30% ryegrass, what percent of the weight of the mixture is X?

A.10%
B.33 1/3%
C.40%
D.50%
E.66 2/3%

B. x = weight of x
40 x + 25 (1-x) = 30
solve for x, x = 33.33%
_________________

Gmat: http://gmatclub.com/forum/everything-you-need-to-prepare-for-the-gmat-revised-77983.html

GT

Kudos [?]: 855 [8], given: 19

Intern
Joined: 26 Feb 2008
Posts: 8

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

### Show Tags

27 Feb 2008, 19:06
1
KUDOS
E.66 2/3%

solve for 25x + 40 [1-x] = 30

so, x = 2/3 = 66 2/3%

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

Director
Joined: 25 Oct 2008
Posts: 594

Kudos [?]: 1182 [33], given: 100

Location: Kolkata,India
Seed mixture X is 40 percent ryegrass and 60 percent [#permalink]

### Show Tags

18 Aug 2009, 00:00
33
KUDOS
24
This post was
BOOKMARKED
Seed mixture X is 40 percent ryegrass and 60 percent bluegrass by weight; seed mixture Y is 25 percent ryegrass and 75 percent fescue. If a mixture of X and Y contains 30 percent ryegrass, what percent of the weight of this mixture is X ?

(A) 10%
(B) 33.33 %
(C) 40%
(D) 50%
(E) 66.66 %

METHOD 1:
Assuming the weight of the mixture to be 100g**, then the weight of ryegrass in the mixture would be 30g.
Also, assume the weight mixture X used in the mixture is Xg, then the weight of mixture Y used in the mixture would be (100-X)g.

So we can now equate the parts of the ryegrass in the mixture as:

0.4X + 0.25(100-X) = 30
0.4X + 25 - 0.25X = 30
0.15X = 5
X = 5/0.15 = 500/15 = 100/3

So the weight of mixture X as a percentage of the weight of the mixture
= (weight of X/weight of mixture) * 100%
= (100/3)/100 * 100%
= 33%

METHOD 2
wt. of 1st mixture = x
therefore concentration of ryegrass in 1st mix = 0.4x

wt. of 2nd mixture = y
therefore concentration of ryegrass in 2nd mix = 0.25y

0.4x+0.25y = 0.3(x+y)

0.4x-0.3x = 0.3y - 0.25y

0.1x=0.05y
or
2x=y

so if weight of x = 50grams
weight of y = 100 grams

total weight of mix = 150 grams

percentage of x in 150 grams of mix is 150*x/100 = 50

x = 50*100/150
x = 100/3
x = 33.3%
_________________

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

Kudos [?]: 1182 [33], given: 100

Intern
Joined: 28 Jan 2010
Posts: 29

Kudos [?]: 71 [16], given: 45

Re: Seed mixture X is ryegrass and bluegrass [#permalink]

### Show Tags

28 Jan 2010, 04:47
16
KUDOS
4
This post was
BOOKMARKED
Let M = x + y

M = New mixture
x = Mixture X
y = Mixture Y

What do we need to find ?? => (x/M)*100

Equating Ryegrass in the mixture -

.4x + 0.25y = 0.3M
.4x + 0.25(M-x) = 0.3M
.4x + 0.25M - 0.25x = 0.3M
.15x = .05M
x/M = 1/3

Hence ans = 33.33%.

Kudos [?]: 71 [16], given: 45

Manager
Joined: 13 Aug 2009
Posts: 149

Kudos [?]: 324 [4], given: 7

WE 1: 4 years in IT
Re: Seed mixture X is ryegrass and bluegrass [#permalink]

### Show Tags

28 Jan 2010, 22:57
4
KUDOS
Hi Tejal777
we can make the method 2 more simpler

METHOD 2
wt. of 1st mixture = x
therefore concentration of ryegrass in 1st mix = 0.4x

wt. of 2nd mixture = y
therefore concentration of ryegrass in 2nd mix = 0.25y

0.4x+0.25y = 0.3(x+y)

0.4x-0.3x = 0.3y - 0.25y

0.1x=0.05y
or
2x=y

[b]so if weight of x = 50grams
weight of y = 100 grams

total weight of mix = 150 grams

percentage of x in 150 grams of mix is 150*x/100 = 50

x = 50*100/150
x = 100/3
x = 33.3%[/b].

what we need is x/x+y *100

we know x and y so solving it we get 33.33%

Kudos [?]: 324 [4], given: 7

Intern
Joined: 27 Aug 2010
Posts: 23

Kudos [?]: 20 [11], given: 2

Re: Seed mixture X is ryegrass and bluegrass [#permalink]

### Show Tags

24 Sep 2010, 23:41
11
KUDOS
1
This post was
BOOKMARKED
IMHO this task is better to solve with absolute numbers.
Say, there are 100 liters of X (40+60) and Y (25+75) that add to 200 liters in total.
The weight of reygrass in the united mixture is 0,3*200=60.
The weight of reygrass in X is 40.
40/60=2/3=33,33%

Kudos [?]: 20 [11], given: 2

Intern
Joined: 13 Oct 2010
Posts: 1

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

Re: Seed mixture X is ryegrass and bluegrass [#permalink]

### Show Tags

13 Oct 2010, 02:11
Sorry, while I understand the explanation, I am bit perplexed on where I am making the mistake

RyeGrass Others
Mixture A 40lb 60lb 100lb
Mixture B 25lb 75lb 100lb
============================
65lb 135lb 200lb

Here 200lbs of mixture will have 65lb of RyeGrass.

In other words, 100lbs of mixture will have 32.5lbs of Ryegrass.

The question is saying - " What % of the weight of the mixture is X"
the mixture here is 100lb and Mixture A is 50lb, so why isn't it (50/100)*100=50%?

I know this is NOT a correct answer but what am I missing?

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

Intern
Joined: 10 Jan 2011
Posts: 19

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

Location: India
Schools: ISB, IIM-A
WE 1: 4 yrs in finance
Re: Seed mixture X is ryegrass and bluegrass [#permalink]

### Show Tags

26 Jan 2011, 08:18
one more way to solve this prob.

since mixture X has 40 percent ryegrass and 60 percent bluegrass i.e they are in ratio of ( 40/60) or ( 2/3)
similarly mixture y has 25 percent ryegrass and 75 percent fescue i.e they are in ratio of ( 25/75) or (1/3)
where as resultant is a mixture in which 30% is ryegrass i.e it is in ratio of ( 30/70) or ( 3/7)

then ryegrass in mixture x = 2/5
ryegrass in mixture y is =1/4

ryegrass in mixture(x+y)= 3/10

then they are mixed in ratio as
quantity of y/ quantity of x= ((2/5)-(3/10))/ ((3/10)-(1/4))= 2 /1

then quantity of x is 1/3 or 33.3%
_________________

Rahul

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

Math Forum Moderator
Joined: 20 Dec 2010
Posts: 1965

Kudos [?]: 2089 [2], given: 376

Re: Seed mixture X is ryegrass and bluegrass [#permalink]

### Show Tags

05 Feb 2011, 05:27
2
KUDOS
take
X=100

In it:
Ryegrass=40
Others = 60

take
Y=y

Ryegrass=0.25y
Others = 0.75y

Mix both;

Total weight:
X+Y=100+y

In it;
Weight of Ryegrass = 40+0.25y

Given:
40+0.25y=0.3(100+y)
40+0.25y=30+0.3y
0.05y=10
y=200

So; total X+Y = 100+200=300
Percentage of X in it: (X/X+Y)*100 = (100/300)*100=100/3=33.33%

Ans: B
_________________

Kudos [?]: 2089 [2], given: 376

Veritas Prep GMAT Instructor
Joined: 16 Oct 2010
Posts: 7736

Kudos [?]: 17782 [19], given: 235

Location: Pune, India

### Show Tags

23 Feb 2011, 19:21
19
KUDOS
Expert's post
9
This post was
BOOKMARKED
Baten80 wrote:
223. Seed mixture X is 40 percent ryegrass and 60 percent
bluegrass by weight; seed mixture Y is 25 percent
ryegrass and 75 percent fescue. If a mixture of X and
Y contains 30 percent ryegrass, what percent of the
weight of the mixture is X ?
(A) 10%
(B) 33 1/3 (33.33%)
(C) 40%
(D) 50%
(E) 66 2/3 (66.66%)

Just focus on ryegrass. X has 40% ryegrass and Y has 25% ryegrass to give 30% ryegrass in mixture. Therefore, X:Y = 1:2 (because distance of X and Y from average is in the ratio 10:5 i.e. 2:1. If this in unclear, check out http://gmatclub.com/forum/tough-ds-105651.html#p828579)
Hence X is 33.33% in the mixture.
_________________

Karishma
Veritas Prep | GMAT Instructor
My Blog

Get started with Veritas Prep GMAT On Demand for \$199

Veritas Prep Reviews

Kudos [?]: 17782 [19], given: 235

Intern
Joined: 04 May 2011
Posts: 17

Kudos [?]: 41 [0], given: 1

Seed mixture X is 40% ryegrass and 60% bluegrass by weight; seed mixtu [#permalink]

### Show Tags

09 May 2011, 06:00
2
This post was
BOOKMARKED
Seed mixture X is 40% ryegrass and 60% bluegrass by weight; seed mixture Y is 25% ryegrass and 75% fescue. If a mixture of X and Y contains 30% ryegrass, what percent of the weight of the mixture is X?

a)10%
b)33.33%
c)40%
d)50%
e)66.67%

Kudos [?]: 41 [0], given: 1

TOEFL Forum Moderator
Joined: 16 Nov 2010
Posts: 1602

Kudos [?]: 600 [0], given: 40

Location: United States (IN)
Concentration: Strategy, Technology
Re: Seed mixture X is 40% ryegrass and 60% bluegrass by weight; seed mixtu [#permalink]

### Show Tags

09 May 2011, 06:23
1
This post was
BOOKMARKED
x - wt of Mix X added
y - wt of Mix Y added

0.4x + 0.25y = 0.3(x+y)

0.1x = 0.05y

x/y = 5/10 = 1/2

y/x = 2

(y+x)/x = 3

=> x/(y+x) * 100 = 100/3 = 33.33%
_________________

Formula of Life -> Achievement/Potential = k * Happiness (where k is a constant)

GMAT Club Premium Membership - big benefits and savings

Kudos [?]: 600 [0], given: 40

VP
Status: There is always something new !!
Affiliations: PMI,QAI Global,eXampleCG
Joined: 08 May 2009
Posts: 1283

Kudos [?]: 286 [0], given: 10

Re: Seed mixture X is 40% ryegrass and 60% bluegrass by weight; seed mixtu [#permalink]

### Show Tags

09 May 2011, 08:34
0.4x + 0.25y = 0.3(x+y)

x/y = 1/2 means x/(x+y) = 1/3 = 33.33% B.
_________________

Visit -- http://www.sustainable-sphere.com/
Promote Green Business,Sustainable Living and Green Earth !!

Kudos [?]: 286 [0], given: 10

Intern
Joined: 15 Mar 2012
Posts: 3

Kudos [?]: 8 [2], given: 0

Location: India
GPA: 3.2
WE: Information Technology (Computer Software)
Re: Seed mixture X is ryegrass and bluegrass [#permalink]

### Show Tags

10 May 2012, 08:10
2
KUDOS
1
This post was
BOOKMARKED
Final Requirement is to calculate "X/(X+Y) * 100"

We have the information about the quantity by weight of ryegrass in X,Y and also the quantity by weight of ryegrass after mixing i.e in X+Y.

So the equation satisfying the above mentioned criteria would be :

(40/100)*X+(25/100)*Y=(30/100)*(X+Y)

Solving this will lead us to the result...

2X=Y

So, the weight percent of X :
(X/X+Y)*100 = (X/X+2X)*100 = 33.33%

Kudos [?]: 8 [2], given: 0

Intern
Joined: 05 Dec 2011
Posts: 47

Kudos [?]: 3 [0], given: 18

Seed mixture X is 40 percent ryegrass and 60 percent [#permalink]

### Show Tags

17 Jul 2012, 11:34
Seed mixture X is 40 percent ryegrass and 60 percent bluegrass by weight; seed mixture Y is 25 percent ryegrass and 75 percent fescue. If a mixture of X and Y contains 30 percent ryegrass, what percent of the weight of this mixture is X ?

(A) 10%
(B) 33.33 %
(C) 40%
(D) 50%
(E) 66.66 %

[Reveal] Spoiler:
1=X+Y --> Y=1-X

(4/10)X+(1/4)Y = (3/10)(X+Y)

(4/10)X+(1/4)(1-X) = (3/10)(x+(1-X))

get common denominator

(16x+(10-10x))/40 = (3/10)

6x+10=12

6x=2

x=2/6 = 1/3 => 33.3%

Can anyone pls expain me how they are taking 1=X+Y.

Pls response. Thanks a lot

Last edited by Bunuel on 26 Oct 2013, 03:23, edited 3 times in total.
Edited the question and added the OA. TOPIC LOCKED

Kudos [?]: 3 [0], given: 18

Director
Joined: 22 Mar 2011
Posts: 610

Kudos [?]: 1072 [0], given: 43

WE: Science (Education)

### Show Tags

17 Jul 2012, 11:43
1
This post was
BOOKMARKED
debabrata44 wrote:
Seed mixture X is 40 percent ryegrass and 60 percent bluegrass by weight; seed mixture Y is 25 percent ryegrass and 75 percent fescue. If a mixture of X and Y contains 30 percent ryegrass, what percent of the weight of this mixture is X ?

(A) 10%
(B) 33.33 %
(C) 40%
(D) 50%
(E) 66.66 %

1=X+Y --> Y=1-X

(4/10)X+(1/4)Y = (3/10)(X+Y)

(4/10)X+(1/4)(1-X) = (3/10)(x+(1-X))

get common denominator

(16x+(10-10x))/40 = (3/10)

6x+10=12

6x=2

x=2/6 = 1/3 => 33.3%

Can anyone pls expain me how they are taking 1=X+Y.

Pls response. Thanks a lot

The question asks "what percent of the weight of this mixture is X".
If we denote by X the percentage of the mixture which is of type X and by Y the percentage of the mixture which is of type Y, then together they must give 100% = 1.
_________________

PhD in Applied Mathematics
Love GMAT Quant questions and running.

Kudos [?]: 1072 [0], given: 43

Manager
Joined: 25 Jun 2012
Posts: 56

Kudos [?]: 23 [1], given: 2

### Show Tags

17 Jul 2012, 21:16
1
KUDOS
It might be easier to think of things in terms of their weight. Assume that you're holding 100kg of the mixture. Of this 100kg, you have a certain amount of kilograms of X, and a certain amount of kilograms of Y. That's where you begin with the X + Y = 1. Note that you also know that there is 30kg of ryegrass in your mixture.

Each kilogram of X would consist of 400g of ryegrass and 600g of bluegrass, while each kilogram of Y would comprise 250g of ryegrass and 750g of fescue. If you want to know how many kilograms of X the mixture contains, you need to work out how you can arrive at 30kg of ryegrass, with exactly 70kg of other stuff (bluegrass + fescue) in the mix. That's what the rest of the working is referring to.

Kudos [?]: 23 [1], given: 2

Senior Manager
Joined: 22 Nov 2010
Posts: 286

Kudos [?]: 179 [5], given: 75

Location: India
GMAT 1: 670 Q49 V33
WE: Consulting (Telecommunications)
Re: Seed mixture X is 40 percent ryegrass and 60 percent [#permalink]

### Show Tags

09 Mar 2013, 00:05
5
KUDOS
5
This post was
BOOKMARKED
RG detail table:

X----------------------------------Y
40%------------------------------25%
-----------------30%--------------
30-25 = 5------------------40-30 = 10

RG ratio 5:10 = 1:2

Therefore, % of X in new mixture = 1/3 = 33.3%
_________________

YOU CAN, IF YOU THINK YOU CAN

Kudos [?]: 179 [5], given: 75

Veritas Prep GMAT Instructor
Joined: 16 Oct 2010
Posts: 7736

Kudos [?]: 17782 [2], given: 235

Location: Pune, India
Re: Seed mixture X is 40 percent ryegrass and 60 percent [#permalink]

### Show Tags

09 Mar 2013, 00:25
2
KUDOS
Expert's post
1
This post was
BOOKMARKED
Sachin9 wrote:
Is this Question correct?

what percent of the weight of this mixture is X ?

And we are answering percent of the ryegrass in X /ryegrass in mixture..

Yes it is. The question tells us that mixture X and mixture Y (both of which are themselves mixtures of ryegrass and bluegrass) are mixed together to give a super mixture. We need to find the weight of mixture X in this super mixture.

We know the % of ryegrass in X and in Y and we also know the % of ryegrass in the super mixture (i.e. the average % of ryegrass when you mix X and Y). This tells us the ratio of X and Y in the super mixture i.e. in what ratio were X and Y mixed together (using our standard weighted averages method). When you have the ratio of X and Y, you can say what the % of mixture X is in the super mixture.

For more on such questions, check out the second example in my post: http://www.veritasprep.com/blog/2011/04 ... -mixtures/
_________________

Karishma
Veritas Prep | GMAT Instructor
My Blog

Get started with Veritas Prep GMAT On Demand for \$199

Veritas Prep Reviews

Kudos [?]: 17782 [2], given: 235

Re: Seed mixture X is 40 percent ryegrass and 60 percent   [#permalink] 09 Mar 2013, 00:25

Go to page    1   2   3    Next  [ 50 posts ]

Display posts from previous: Sort by

# Seed mixture X is 40 percent ryegrass and 60 percent

 Powered by phpBB © phpBB Group | Emoji artwork provided by EmojiOne 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®.