GMAT Question of the Day - Daily to your Mailbox; hard ones only

It is currently 15 Oct 2018, 12:48

Oct 15

Darden EA Calls have started. Join the Darden Chat or Darden Forum Discussion or Darden Decision Tracker


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.

Close

Request Expert Reply

Confirm Cancel

Solution Y is 30 percent liquid X and 70 percent water. If 2 kilogram

  new topic post reply Question banks Downloads My Bookmarks Reviews Important topics  
Author Message
TAGS:

Hide Tags

Intern
Intern
avatar
Joined: 19 Dec 2009
Posts: 27
Solution Y is 30 percent liquid X and 70 percent water. If 2 kilogram  [#permalink]

Show Tags

New post 08 Nov 2010, 14:02
2
16
00:00
A
B
C
D
E

Difficulty:

  45% (medium)

Question Stats:

75% (02:43) correct 25% (02:52) wrong based on 554 sessions

HideShow timer Statistics

Solution Y is 30 percent liquid X and 70 percent water. If 2 kilograms of water evaporate from 8 kilograms of solutions Y and 2 kilograms of solution Y are added to the remaining 6 kilograms of liquid, what percent of this new liquid solution is liquid X?

A. 30%
B. 33 1/3%
C. 37 1/2%
D. 40%
E. 50%
Most Helpful Expert Reply
Math Expert
User avatar
V
Joined: 02 Sep 2009
Posts: 49858
Re: percent word problem  [#permalink]

Show Tags

New post 06 Apr 2012, 13:19
2
4
rovshan85 wrote:
Solution Y is 30% liquid X and 70 percent water. If 2 kilograms of water evaporate from 8 kg of solution Y and 2 kg of solution Y are added to the remaining 6 kg of liquid, what percent of this new solution is liquid X?

a. 30
b. 33 1/3
c. 37 1/2
d. 40
e. 50

What is the easiest way to approach this type of problem and solve under 2 min.


In 8 kilograms of solution Y there are 0.3*8=2.4 kilograms of solution X;

After 2 kilograms of water are replaced by 2 kilograms of solution Y, to the existing 2.4 kilograms of solution X, 0.3*2=0.6 kilograms of solution X are added, so in the new solution of 8 kilograms there are 2.4+0.6=3 kilograms of solution X, which is 3/8*100=37.5% of this new solution.

Answer: C.
_________________

New to the Math Forum?
Please read this: Ultimate GMAT Quantitative Megathread | All You Need for Quant | PLEASE READ AND FOLLOW: 12 Rules for Posting!!!

Resources:
GMAT Math Book | Triangles | Polygons | Coordinate Geometry | Factorials | Circles | Number Theory | Remainders; 8. Overlapping Sets | PDF of Math Book; 10. Remainders | GMAT Prep Software Analysis | SEVEN SAMURAI OF 2012 (BEST DISCUSSIONS) | Tricky questions from previous years.

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?
Extra-hard Quant Tests with Brilliant Analytics

Most Helpful Community Reply
Intern
Intern
avatar
Joined: 24 Aug 2010
Posts: 5
Re: Solution Y is 30 percent liquid X and 70 percent water. If 2 kilogram  [#permalink]

Show Tags

New post 08 Nov 2010, 14:16
2
3
At the beggining, you have 8KG of solution Y, i.e.

70% * 8KG = 5,6 KG of Water
30% * 8KG = 2,4 KG of X

2KG of water evaporate:

5,6KG - 2KG = 3,6KG of Water
2,4KG of X

2KG of liquid are added:

3,6KG + 2*0,70 = 5KG of Water
2,4KG + 2*0,30 = 3 KG of X

So you have 3KG of X in 8KG (3 + 5) solution.
Therefore X concentration is 3/8 = 37,5%
General Discussion
Senior Manager
Senior Manager
User avatar
Status: Not afraid of failures, disappointments, and falls.
Joined: 20 Jan 2010
Posts: 270
Concentration: Technology, Entrepreneurship
WE: Operations (Telecommunications)
GMAT ToolKit User Premium Member
Re: Solution Y is 30 percent liquid X and 70 percent water. If 2 kilogram  [#permalink]

Show Tags

New post 09 Nov 2010, 00:01
1
Answer:C
Took time to solve this one, the statement 2 kilograms of solution Y are added to the remaining 6 kilograms of liquid was confusing to me. After thinking more deeply, it was clear to me that new 2 kg of solution Y will also be 30% liquid X and 70% water, and then I was able to get the answer. That was a bit tricky and nice question.
Kudos +1 for posting the question :)
_________________

"I choose to rise after every fall"
Target=770
http://challengemba.blogspot.com
Kudos??

Retired Moderator
User avatar
Joined: 02 Sep 2010
Posts: 769
Location: London
GMAT ToolKit User Reviews Badge
Re: Solution Y is 30 percent liquid X and 70 percent water. If 2 kilogram  [#permalink]

Show Tags

New post 09 Nov 2010, 00:25
1
Initially you start with 8kg of solution which has 2.4kg of X and 5.6kg of water
Post evaporation : 2.4kg of X and 3.6kg of water
Now we add back 2kg of Y --> 1.4Kg water + 0.6Kg X
So we have left 5Kg Water & 3Kg X

Percentage concentration is (3/5)*100 or 37.5%
_________________

Math write-ups
1) Algebra-101 2) Sequences 3) Set combinatorics 4) 3-D geometry

My GMAT story

GMAT Club Premium Membership - big benefits and savings

Senior Manager
Senior Manager
User avatar
Status: Not afraid of failures, disappointments, and falls.
Joined: 20 Jan 2010
Posts: 270
Concentration: Technology, Entrepreneurship
WE: Operations (Telecommunications)
GMAT ToolKit User Premium Member
Re: Solution Y is 30 percent liquid X and 70 percent water. If 2 kilogram  [#permalink]

Show Tags

New post 09 Nov 2010, 00:43
shrouded1 wrote:
Initially you start with 8kg of solution which has 2.4kg of X and 5.6kg of water
Post evaporation : 2.4kg of X and 3.6kg of water
Now we add back 2kg of Y --> 1.4Kg water + 0.6Kg X
So we have left 5Kg Water & 3Kg X

Percentage concentration is (3/5)*100 or 37.5%

Yea, that's exactly how I solved but you know at first I was kinda adding 2 to 6 kg without considering liquid X and water's concentration within 2 kg being added.
_________________

"I choose to rise after every fall"
Target=770
http://challengemba.blogspot.com
Kudos??

Director
Director
User avatar
B
Status: No dream is too large, no dreamer is too small
Joined: 14 Jul 2010
Posts: 512
Re: Solution Y is 30 percent liquid X and 70 percent water. If 2 kilogram  [#permalink]

Show Tags

New post 10 Dec 2011, 13:51
1
Liquid x in 8 kg = 8*30%=12/5
Liquid x in next 2 kg = 2*30% = 3/5
Total x = 12/5 + 3/5 = 15/5 = 3
so, (3/8)*100= 37.5%
Ans. C
_________________

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
avatar
Joined: 26 Apr 2011
Posts: 213
GMAT ToolKit User Reviews Badge
Re: Solution Y is 30 percent liquid X and 70 percent water. If 2 kilogram  [#permalink]

Show Tags

New post 11 Dec 2011, 23:43
Initially we have 8kg of solution which has 3/10 0f 8= 2.4kg of X and 7/10 of 8 = 5.6kg of water after evaporation : 2.4kg of X and 3.6kg of water
Now we added 2kg of solution Y --> 7/10 of 2=1.4Kg water + 3/10 0f 2 =0.6Kg X
So we have left 5Kg Water & 3Kg X

Percentage concentration is (3/5)*100 or 37.5%
Manager
Manager
User avatar
Joined: 28 Jul 2011
Posts: 190
Solution Y is 30 percent liquid X and 70 percent water. If 2  [#permalink]

Show Tags

New post 02 Jun 2012, 09:51
Solution Y total = 8
Liq x = 30% (8) = 2.4

Added 2 kg of Solution Y
Liq x = 30% (2) = 0.6

Final Solution wil have = (2.4 + 0.6) = 3 kg of Liq x

3/8 = 37.5%
Director
Director
User avatar
B
Joined: 17 Dec 2012
Posts: 629
Location: India
Re: Solution Y is 30 percent liquid X and 70 percent water. If 2  [#permalink]

Show Tags

New post 26 Aug 2013, 21:32
1
rovshan85 wrote:
Solution Y is 30 percent liquid X and 70 percent water. If 2 kilograms of water evaporate from 8 kilograms of solution Y and 2 kilograms of solution Y are added to the remaining 6 kilograms of liquid, what percent of this new solution is liquid X?

A. 30%
B. 33 1/3%
C. 37 1/2%
D. 40%
E. 50%

What is the easiest way to approach this type of problem and solve under 2 min.


1. The net effect of 2 kg of water evaporating and adding 2 kg of the solution is removing (-2 + 1.4 = -0.6) 0.6 kg of water and adding 0.6 kg of liquid
2 Therefore the changed solution contains, 2.4 + 0.6 = 3 kg of liquid and 5.6-0.6==5 kg of water.
3. Percentage of liquid is 3/8 * 100 % = 37 1/2 %
_________________

Srinivasan Vaidyaraman
Sravna Holistic Solutions
http://www.sravnatestprep.com

Holistic and Systematic Approach

Senior Manager
Senior Manager
User avatar
Joined: 20 Aug 2015
Posts: 391
Location: India
GMAT 1: 760 Q50 V44
Re: Solution Y is 30 percent liquid X and 70 percent water. If 2 kilogram  [#permalink]

Show Tags

New post 05 Jan 2016, 05:55
rtaha2412 wrote:
Solution Y is 30 percent liquid X and 70 percent water. If 2 kilograms of water evaporate from 8 kilograms of solutions Y and 2 kilograms of solution Y are added to the remaining 6 kilograms of liquid, what percent of this new liquid solution is liquid X?

A. 30%
B. 33 1/3%
C. 37 1/2%
D. 40%
E. 50%


The best way to solve these problems is to take one step at a time

Initial:
8 kg Solution Y
This means Solution X = 2.4 kg, Water = 5.6 kg

Step 2:
2 kg of water is evaporated.
Left over: Solution X = 2.4 kg and Water = 3.6 kg

Step 3:
2 kg of Solutoin Y is added
Or, 0.6 kg of Solution X and 1.4 kg of water is added

Final:
Solution X = 3, Water = 5
% of solution X = 3/8 * 100 = 37.5%

Option C
Intern
Intern
avatar
Joined: 01 Feb 2016
Posts: 1
Re: Solution Y is 30 percent liquid X and 70 percent water. If 2 kilogram  [#permalink]

Show Tags

New post 03 May 2016, 07:47
rtaha2412 wrote:
Solution Y is 30 percent liquid X and 70 percent water. If 2 kilograms of water evaporate from 8 kilograms of solutions Y and 2 kilograms of solution Y are added to the remaining 6 kilograms of liquid, what percent of this new liquid solution is liquid X?

A. 30%
B. 33 1/3%
C. 37 1/2%
D. 40%
E. 50%



Hi,

I like using a table for mixture problems. This is what I came up with (see attachement):
Attachments

Sol gmat.JPG
Sol gmat.JPG [ 31.44 KiB | Viewed 5586 times ]

VP
VP
avatar
P
Joined: 07 Dec 2014
Posts: 1102
Solution Y is 30 percent liquid X and 70 percent water. If 2 kilogram  [#permalink]

Show Tags

New post Updated on: 28 Feb 2018, 22:08
Solution Y is 30 percent liquid X and 70 percent water. If 2 kilograms of water evaporate from 8 kilograms of solutions Y and 2 kilograms of solution Y are added to the remaining 6 kilograms of liquid, what percent of this new liquid solution is liquid X?

A. 30%
B. 33 1/3%
C. 37 1/2%
D. 40%
E. 50%

let x=% of liquid X in new solution
.3*8+.3*2=x(6+2)
x=3/8=37.5%
C

Originally posted by gracie on 18 Jul 2016, 20:23.
Last edited by gracie on 28 Feb 2018, 22:08, edited 1 time in total.
Manager
Manager
avatar
S
Joined: 14 Jul 2014
Posts: 103
Location: India
Concentration: Social Entrepreneurship, Strategy
GMAT 1: 620 Q41 V34
WE: Information Technology (Computer Software)
Re: Solution Y is 30 percent liquid X and 70 percent water. If 2 kilogram  [#permalink]

Show Tags

New post 22 Sep 2018, 06:52
1
DS00 wrote:
rtaha2412 wrote:
Solution Y is 30 percent liquid X and 70 percent water. If 2 kilograms of water evaporate from 8 kilograms of solutions Y and 2 kilograms of solution Y are added to the remaining 6 kilograms of liquid, what percent of this new liquid solution is liquid X?

A. 30%
B. 33 1/3%
C. 37 1/2%
D. 40%
E. 50%



Hi,

I like using a table for mixture problems. This is what I came up with (see attachement):


I also used the similar approach.
To Sum up:
Initial 8 kilograms of Y consist of 2.4 kg X and 5.6 kg water.
We then lose 2 kg water to evaporation, so we are down to 3.6 kg water.
The final step adds 2 kg Y, which consists of .6 kg X and 1.4 kg water.
Therefore, the final mixture contains 3 kg X and 5 kg water. 3/8 = 37.5%.
GMAT Club Bot
Re: Solution Y is 30 percent liquid X and 70 percent water. If 2 kilogram &nbs [#permalink] 22 Sep 2018, 06:52
Display posts from previous: Sort by

Solution Y is 30 percent liquid X and 70 percent water. If 2 kilogram

  new topic post reply Question banks Downloads My Bookmarks Reviews Important topics  


Copyright

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

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®.