It is currently 15 Dec 2017, 13:53

# Decision(s) Day!:

CHAT Rooms | Olin (St. Louis) R1 | Tuck R1 | Ross R1 | Fuqua R1

### 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

# What percent of the mixture is Solution X?

Author Message
TAGS:

### Hide Tags

Intern
Joined: 06 Sep 2012
Posts: 41

Kudos [?]: 55 [2], given: 42

Concentration: Social Entrepreneurship
What percent of the mixture is Solution X? [#permalink]

### Show Tags

08 Dec 2012, 10:49
2
KUDOS
3
This post was
BOOKMARKED
00:00

Difficulty:

25% (medium)

Question Stats:

73% (01:41) correct 27% (01:38) wrong based on 261 sessions

### HideShow timer Statistics

Solution X is 20% chemical A and 80% chemical B by volume; Solution Y is 30% chemical A and 70% chemical B. If a mixture of X and Y is 22% chemical A, what percent of the mixture is Solution X?

A) 20%
B) 44%
C) 50%
D) 80%
E) 90%

Can someone please also direct me to a page in gmatclub that has similar mixture problems? Thanks!
[Reveal] Spoiler: OA

Kudos [?]: 55 [2], given: 42

Senior Manager
Joined: 22 Dec 2011
Posts: 295

Kudos [?]: 305 [1], given: 32

Re: What percent of the mixture is Solution X? [#permalink]

### Show Tags

08 Dec 2012, 11:03
1
KUDOS
2
This post was
BOOKMARKED
JJ2014 wrote:
Solution X is 20% chemical A and 80% chemical B by volume; Solution Y is 30% chemical A and 70% chemical B. If a mixture of X and Y is 22% chemical A, what percent of the mixture is Solution X?

A) 20%
B) 44%
C) 50%
D) 80%
E) 90%

Can someone please also direct me to a page in gmatclub that has similar mixture problems? Thanks!

you can solve this by allegation method.
Given 22% of A is the final mixture; Sol X has 20% chemical A and Sol Y has 30 % of A. (you don't need Chemical B to solve when you r solving the problem using this method)

$$X / Y = (30-22 ) / (22-20)$$
$$X / Y = 8/2 = 4/1$$

So X and Y are in the ratio 4 : 1
Question asks percent of the mixture is Solution X.

So $$X / Total = 4/5 *100 = 80%$$

Cheers

Kudos [?]: 305 [1], given: 32

Board of Directors
Joined: 01 Sep 2010
Posts: 3423

Kudos [?]: 9522 [3], given: 1203

Re: What percent of the mixture is Solution X? [#permalink]

### Show Tags

08 Dec 2012, 11:16
3
KUDOS
also you can solve this one with the concept of weighted average or balance point

you care about only of chemical A in both X and Y

$$20$$------- $$22$$ ------------------------$$30$$

Now the difference between 20 and 22 = 2; between 22 and 30 = 8

So $$8y = 2 x$$

$$\frac{8}{2}$$ $$=$$$$\frac{x}{y}$$
Our ratio is 2 and 8 and using the concept of unknown multiplier the sum is 10. Our X is 8 on a total of 10 so 80 %

much more difficult to say that to explain. In that way you can solve a question difficult like this in 30 seconds.

Also algebraic approach works fine, but this is a bit faster
_________________

Kudos [?]: 9522 [3], given: 1203

Manager
Joined: 06 Jun 2010
Posts: 157

Kudos [?]: 20 [2], given: 151

Re: What percent of the mixture is Solution X? [#permalink]

### Show Tags

09 Dec 2012, 00:29
2
KUDOS

Kudos [?]: 20 [2], given: 151

Math Expert
Joined: 02 Sep 2009
Posts: 42618

Kudos [?]: 135755 [2], given: 12708

Re: What percent of the mixture is Solution X? [#permalink]

### Show Tags

09 Dec 2012, 05:31
2
KUDOS
Expert's post
JJ2014 wrote:
Solution X is 20% chemical A and 80% chemical B by volume; Solution Y is 30% chemical A and 70% chemical B. If a mixture of X and Y is 22% chemical A, what percent of the mixture is Solution X?

A) 20%
B) 44%
C) 50%
D) 80%
E) 90%

Can someone please also direct me to a page in gmatclub that has similar mixture problems? Thanks!

22% of chemical A in X+Y grams of solution comes from 20% chemical A in solution X and 30% chemical A in solution Y, thus:

0.22(X + Y) = 0.2X + 0.3Y --> X = 4Y --> X/(X+Y)=4/5=0.8.

Check out question banks for similar problems:
DS mixture problems: search.php?search_id=tag&tag_id=43
PS mixture problems: search.php?search_id=tag&tag_id=114

Hope it helps.
_________________

Kudos [?]: 135755 [2], given: 12708

Senior Manager
Joined: 22 Nov 2010
Posts: 285

Kudos [?]: 182 [1], given: 75

Location: India
GMAT 1: 670 Q49 V33
WE: Consulting (Telecommunications)
Re: What percent of the mixture is Solution X? [#permalink]

### Show Tags

08 Mar 2013, 23:14
1
KUDOS
JJ2014 wrote:
Solution X is 20% chemical A and 80% chemical B by volume; Solution Y is 30% chemical A and 70% chemical B. If a mixture of X and Y is 22% chemical A, what percent of the mixture is Solution X?

A) 20%
B) 44%
C) 50%
D) 80%
E) 90%

Can someone please also direct me to a page in gmatclub that has similar mixture problems? Thanks!

Focus on Chemical A:

X--------------------------------------Y
20%---------------------------------30%

--------------------22%-----------------

30 - 22= 8--------------------22-20 = 2

X:Y = 8:2 = 4:1.

Therefore, %age of X = 4/5 * 100 = 80%
_________________

YOU CAN, IF YOU THINK YOU CAN

Kudos [?]: 182 [1], given: 75

Non-Human User
Joined: 09 Sep 2013
Posts: 14830

Kudos [?]: 288 [0], given: 0

Re: What percent of the mixture is Solution X? [#permalink]

### Show Tags

02 Feb 2015, 05:27
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.
_________________

Kudos [?]: 288 [0], given: 0

EMPOWERgmat Instructor
Status: GMAT Assassin/Co-Founder
Affiliations: EMPOWERgmat
Joined: 19 Dec 2014
Posts: 10401

Kudos [?]: 3693 [0], given: 173

Location: United States (CA)
GMAT 1: 800 Q51 V49
GRE 1: 340 Q170 V170
Re: What percent of the mixture is Solution X? [#permalink]

### Show Tags

02 Feb 2015, 12:11
Expert's post
1
This post was
BOOKMARKED
Hi All,

These types of mixture questions can typically be solved with a variety of approaches (the average formula, ratios, TESTing VALUES, TESTing THE ANSWERS, etc.). Here's the standard Weighted Average Formula approach:

Solution X = 20% chemical A
Solution Y = 30% chemical A

Mixture of the two solutions = 22% chemical A

X = number of ounces of Solution X
Y = number of ounces of Solution Y

(.2X + .3Y) / (X + Y) = .22

.2X + .3Y = .22X + .22Y
.08Y = .02X

We can multiply both sides by 100 to get rid of the decimals...

8Y = 2X

The question asks for the percentage of the new mixture that is Solution X....

8/2 = X/Y
4/1 = X/Y

80% X and 20% Y

[Reveal] Spoiler:
D

GMAT assassins aren't born, they're made,
Rich
_________________

760+: Learn What GMAT Assassins Do to Score at the Highest Levels
Contact Rich at: Rich.C@empowergmat.com

# Rich Cohen

Co-Founder & GMAT Assassin

Special Offer: Save \$75 + GMAT Club Tests Free
Official GMAT Exam Packs + 70 Pt. Improvement Guarantee
www.empowergmat.com/

***********************Select EMPOWERgmat Courses now include ALL 6 Official GMAC CATs!***********************

Kudos [?]: 3693 [0], given: 173

Senior Manager
Status: DONE!
Joined: 05 Sep 2016
Posts: 408

Kudos [?]: 26 [0], given: 283

Re: What percent of the mixture is Solution X? [#permalink]

### Show Tags

27 Oct 2016, 15:22
0.20x+(1-x)0.30 = 0.22
0.20x+0.30-0.30x=0.22
-0.10x=-0.08
x=4/5 = 80%

Kudos [?]: 26 [0], given: 283

Manager
Joined: 26 Jan 2016
Posts: 115

Kudos [?]: 24 [0], given: 55

Location: United States
GPA: 3.37
Re: What percent of the mixture is Solution X? [#permalink]

### Show Tags

27 Oct 2016, 15:40
If the solution is 22% of A we know off the bat that the majority of the solution has to be X. We can eliminate A,B,C.

Solution X is 20% A and Y is 30

So X is 2 units from the combo and Y is 8 units away.

Ration of X:Y for solution A is 8:2
8/10=80%

Kudos [?]: 24 [0], given: 55

Re: What percent of the mixture is Solution X?   [#permalink] 27 Oct 2016, 15:40
Display posts from previous: Sort by