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

It is currently 01 Sep 2015, 04:29
GMAT Club Tests

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 vessel has 300 ml of pure milk. 30 ml of milk is removed and 30 ml

  Question banks Downloads My Bookmarks Reviews Important topics  
Author Message
TAGS:
1 KUDOS received
Manager
Manager
avatar
Joined: 10 Jan 2010
Posts: 117
GPA: 4
WE: Programming (Computer Software)
Followers: 0

Kudos [?]: 76 [1] , given: 33

A vessel has 300 ml of pure milk. 30 ml of milk is removed and 30 ml [#permalink] New post 08 Oct 2011, 16:42
1
This post received
KUDOS
00:00
A
B
C
D
E

Difficulty:

(N/A)

Question Stats:

0% (00:00) correct 100% (02:32) wrong based on 2 sessions
A vessel has 300 ml of pure milk. 30 ml of milk is removed and 30 ml of water is added into the vessel. If this operation is repeated another 2 times, what is the % of milk in the vessel at the end?.
_________________

-If you like my post, consider giving KUDOS

Director
Director
avatar
Joined: 01 Feb 2011
Posts: 759
Followers: 14

Kudos [?]: 75 [0], given: 42

Re: A vessel has 300 ml of pure milk. 30 ml of milk is removed and 30 ml [#permalink] New post 08 Oct 2011, 18:17
Milk----Water

300---------0
270---------30 after 1st removal
270-15------30-15+30
270-15-15---30-15+30-15+30 after two more removals

% of milk after two more removals =(240/300)*100 = 80 %

Last edited by Spidy001 on 09 Oct 2011, 08:17, edited 1 time in total.
Senior Manager
Senior Manager
avatar
Joined: 13 May 2011
Posts: 319
WE 1: IT 1 Yr
WE 2: Supply Chain 5 Yrs
Followers: 19

Kudos [?]: 164 [0], given: 11

Re: A vessel has 300 ml of pure milk. 30 ml of milk is removed and 30 ml [#permalink] New post 08 Oct 2011, 22:27
Total MIlk Removed= 30+30+30=90 ml
Remaining Milk= 300-90 = 210 ml
% of Milk = 210/300=7/10=70%
3 KUDOS received
Manager
Manager
User avatar
Status: Trying hard to give another shot!
Joined: 29 Jun 2010
Posts: 113
GMAT 1: 610 Q45 V29
WE: Information Technology (Computer Software)
Followers: 1

Kudos [?]: 31 [3] , given: 50

Reviews Badge CAT Tests
Re: A vessel has 300 ml of pure milk. 30 ml of milk is removed and 30 ml [#permalink] New post 09 Oct 2011, 01:48
3
This post received
KUDOS
maheshsrini wrote:
A vessel has 300 ml of pure milk. 30 ml of milk is removed and 30 ml of water is added into the vessel. If this operation is repeated another 2 times, what is the % of milk in the vessel at the end?.


You can solve these kind of questions with a standard formula..

If there is P volume of pure liquid initially and in each operation ,Q volume is take out and replaced by Q volume of water ,then at the end of n such operations ,the concentration (k) of the liquid in the solution is given by

{ (P-Q)/P }^n = k

This gives the concentration (k) of the liquid as a PROPORTION of the total volume of the solution.
If concentration has to be expressed as percentage ,then it will be 100k.

Here , we have P= 300 ; Q = 30 and n =3(2+1)

{(300-30)/300}^3 = (9/10)^3 = 0.729

Therefore the percentage of the alcohol in the vessel is 72.9 % .
_________________

Thanks,
GC24


Please click Kudos ,if my post helped you ;)

Manager
Manager
avatar
Joined: 20 Nov 2010
Posts: 225
Followers: 4

Kudos [?]: 9 [0], given: 38

Re: A vessel has 300 ml of pure milk. 30 ml of milk is removed and 30 ml [#permalink] New post 09 Oct 2011, 09:09
gmatcracker24 seems like a big fan of alcohol. Its milk in here dude :)

gmatcracker24 wrote:
maheshsrini wrote:
A vessel has 300 ml of pure milk. 30 ml of milk is removed and 30 ml of water is added into the vessel. If this operation is repeated another 2 times, what is the % of milk in the vessel at the end?.


You can solve these kind of questions with a standard formula..

If there is P volume of pure liquid initially and in each operation ,Q volume is take out and replaced by Q volume of water ,then at the end of n such operations ,the concentration (k) of the liquid in the solution is given by

{ (P-Q)/P }^n = k

This gives the concentration (k) of the liquid as a PROPORTION of the total volume of the solution.
If concentration has to be expressed as percentage ,then it will be 100k.

Here , we have P= 300 ; Q = 30 and n =3(2+1)

{(300-30)/300}^3 = (9/10)^3 = 0.729

Therefore the percentage of the alcohol in the vessel is 72.9 % .

_________________

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
MGMAT 6 650 (51,31) on 31/8/11
MGMAT 1 670 (48,33) on 04/9/11
MGMAT 2 670 (47,34) on 07/9/11
MGMAT 3 680 (47,35) on 18/9/11
GMAT Prep1 680 ( 50, 31) on 10/11/11

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
CR notes
http://gmatclub.com/forum/massive-collection-of-verbal-questions-sc-rc-and-cr-106195.html#p832142
http://gmatclub.com/forum/1001-ds-questions-file-106193.html#p832133
http://gmatclub.com/forum/gmat-prep-critical-reasoning-collection-106783.html
http://gmatclub.com/forum/how-to-get-6-0-awa-my-guide-64327.html
http://gmatclub.com/forum/how-to-get-6-0-awa-my-guide-64327.html?hilit=chineseburned

Manager
Manager
avatar
Joined: 20 Nov 2010
Posts: 225
Followers: 4

Kudos [?]: 9 [0], given: 38

Re: A vessel has 300 ml of pure milk. 30 ml of milk is removed and 30 ml [#permalink] New post 09 Oct 2011, 09:14
The formula { ( p-q)/p } ^n gives the %age of pure liquid left
where q is volume of liquid taken out of p and replaced by another liquid (same quantity)
n is the number of times this process is repeated.

eg in our case pure MILK = { (300-30)/300 }^3 * 300 = 729/1000 * 300 = 218.7
%age of pure milk is { (300-30)/300 }^3 = 72.9 %
_________________

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
MGMAT 6 650 (51,31) on 31/8/11
MGMAT 1 670 (48,33) on 04/9/11
MGMAT 2 670 (47,34) on 07/9/11
MGMAT 3 680 (47,35) on 18/9/11
GMAT Prep1 680 ( 50, 31) on 10/11/11

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
CR notes
http://gmatclub.com/forum/massive-collection-of-verbal-questions-sc-rc-and-cr-106195.html#p832142
http://gmatclub.com/forum/1001-ds-questions-file-106193.html#p832133
http://gmatclub.com/forum/gmat-prep-critical-reasoning-collection-106783.html
http://gmatclub.com/forum/how-to-get-6-0-awa-my-guide-64327.html
http://gmatclub.com/forum/how-to-get-6-0-awa-my-guide-64327.html?hilit=chineseburned


Last edited by catfreak on 12 Oct 2011, 20:34, edited 1 time in total.
Manager
Manager
User avatar
Status: Trying hard to give another shot!
Joined: 29 Jun 2010
Posts: 113
GMAT 1: 610 Q45 V29
WE: Information Technology (Computer Software)
Followers: 1

Kudos [?]: 31 [0], given: 50

Reviews Badge CAT Tests
Re: A vessel has 300 ml of pure milk. 30 ml of milk is removed and 30 ml [#permalink] New post 09 Oct 2011, 09:16
catfreak wrote:
gmatcracker24 seems like a big fan of alcohol. Its milk in here dude :)

gmatcracker24 wrote:
maheshsrini wrote:
A vessel has 300 ml of pure milk. 30 ml of milk is removed and 30 ml of water is added into the vessel. If this operation is repeated another 2 times, what is the % of milk in the vessel at the end?.


You can solve these kind of questions with a standard formula..

If there is P volume of pure liquid initially and in each operation ,Q volume is take out and replaced by Q volume of water ,then at the end of n such operations ,the concentration (k) of the liquid in the solution is given by

{ (P-Q)/P }^n = k

This gives the concentration (k) of the liquid as a PROPORTION of the total volume of the solution.
If concentration has to be expressed as percentage ,then it will be 100k.

Here , we have P= 300 ; Q = 30 and n =3(2+1)

{(300-30)/300}^3 = (9/10)^3 = 0.729

Therefore the percentage of the alcohol in the vessel is 72.9 % .


lol :) I am not a big fan of alcohol bro...neither fan of milk ;) but unfortunately these kind of questions always have either alcohol or milk ...in it :)
_________________

Thanks,
GC24


Please click Kudos ,if my post helped you ;)

Manager
Manager
avatar
Joined: 10 Jan 2010
Posts: 117
GPA: 4
WE: Programming (Computer Software)
Followers: 0

Kudos [?]: 76 [0], given: 33

Re: A vessel has 300 ml of pure milk. 30 ml of milk is removed and 30 ml [#permalink] New post 10 Oct 2011, 18:55
But why is there a difference of 2.9% between the formula and the trial version?. Can somebody pls explain?
_________________

-If you like my post, consider giving KUDOS

Manager
Manager
User avatar
Status: Trying hard to give another shot!
Joined: 29 Jun 2010
Posts: 113
GMAT 1: 610 Q45 V29
WE: Information Technology (Computer Software)
Followers: 1

Kudos [?]: 31 [0], given: 50

Reviews Badge CAT Tests
Re: A vessel has 300 ml of pure milk. 30 ml of milk is removed and 30 ml [#permalink] New post 10 Oct 2011, 21:18
maheshsrini wrote:
But why is there a difference of 2.9% between the formula and the trial version?. Can somebody pls explain?


There should not be any difference between both.The difference is because in the trial versions they have removed the milk 30+30+30 which is not correct because after the first operation 30 litre of water is mixed to the solution ,and next operation onwards 30 litre removed contains water + milk. The approach should have been different.

The formula takes care of these conditions and hence accurate.
_________________

Thanks,
GC24


Please click Kudos ,if my post helped you ;)

Senior Manager
Senior Manager
avatar
Joined: 13 May 2011
Posts: 319
WE 1: IT 1 Yr
WE 2: Supply Chain 5 Yrs
Followers: 19

Kudos [?]: 164 [0], given: 11

Re: A vessel has 300 ml of pure milk. 30 ml of milk is removed and 30 ml [#permalink] New post 10 Oct 2011, 22:38
I am not sure if the question is flawed or not. However, if we are NOT losing any solution after each operation the Final Solution should be 300 ml. In that case, I think, we must have 210 (300-90) ml Milk in the 300 ml Solution.

However, If we are taking out solution only to have 30 ml Milk: in the second operation we must take out 33.33 ml solution to have 30 ml of milk of which 3.33 ml will be water, because after the 1st operation 90% of the solution is Milk. Therefore, after the 2nd operation we will have 296.67 ml of solution.
If we continue the process: after the 3rd operation we have 289.59 ml of the solution of which 210 ml is milk. The left over milk is 72.5%+ of the solution.

Here we are assuming that we must take out as much solution as to have 30 ml of milk. Hence, we are losing approximately 10.41 ml of the water.

Can someone please verify?
Manager
Manager
avatar
Joined: 20 Nov 2010
Posts: 225
Followers: 4

Kudos [?]: 9 [0], given: 38

Re: A vessel has 300 ml of pure milk. 30 ml of milk is removed and 30 ml [#permalink] New post 12 Oct 2011, 20:42
Nice observation there.

Most of the solutions including mine assumes that we are removing 30ml solution and not 30ml Milk but the question says otherwise.
Having said that, one can't just remove Milk from the mixture it has to be a solution ( with some water and milk in some %ages).
Generally in such type of questions its the solution that is removed.
So i think the question should clarify this more.
Someone with better explanation, please clarify.

BDSunDevil wrote:
I am not sure if the question is flawed or not. However, if we are NOT losing any solution after each operation the Final Solution should be 300 ml. In that case, I think, we must have 210 (300-90) ml Milk in the 300 ml Solution.

However, If we are taking out solution only to have 30 ml Milk: in the second operation we must take out 33.33 ml solution to have 30 ml of milk of which 3.33 ml will be water, because after the 1st operation 90% of the solution is Milk. Therefore, after the 2nd operation we will have 296.67 ml of solution.
If we continue the process: after the 3rd operation we have 289.59 ml of the solution of which 210 ml is milk. The left over milk is 72.5%+ of the solution.

Here we are assuming that we must take out as much solution as to have 30 ml of milk. Hence, we are losing approximately 10.41 ml of the water.

Can someone please verify?

_________________

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
MGMAT 6 650 (51,31) on 31/8/11
MGMAT 1 670 (48,33) on 04/9/11
MGMAT 2 670 (47,34) on 07/9/11
MGMAT 3 680 (47,35) on 18/9/11
GMAT Prep1 680 ( 50, 31) on 10/11/11

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
CR notes
http://gmatclub.com/forum/massive-collection-of-verbal-questions-sc-rc-and-cr-106195.html#p832142
http://gmatclub.com/forum/1001-ds-questions-file-106193.html#p832133
http://gmatclub.com/forum/gmat-prep-critical-reasoning-collection-106783.html
http://gmatclub.com/forum/how-to-get-6-0-awa-my-guide-64327.html
http://gmatclub.com/forum/how-to-get-6-0-awa-my-guide-64327.html?hilit=chineseburned

GMAT Club Legend
GMAT Club Legend
User avatar
Joined: 09 Sep 2013
Posts: 6151
Followers: 342

Kudos [?]: 70 [0], given: 0

Premium Member
Re: A vessel has 300 ml of pure milk. 30 ml of milk is removed and 30 ml [#permalink] New post 18 Aug 2015, 23:34
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.
_________________

GMAT Books | GMAT Club Tests | Best Prices on GMAT Courses | GMAT Mobile App | Math Resources | Verbal Resources

Re: A vessel has 300 ml of pure milk. 30 ml of milk is removed and 30 ml   [#permalink] 18 Aug 2015, 23:34
    Similar topics Author Replies Last post
Similar
Topics:
1 Experts publish their posts in the topic What strength of 20 ml alcohol should be added to 10ml of 50 Bunuel 2 07 Feb 2014, 02:26
5 Experts publish their posts in the topic In a LAB experiment, a 100 ml compound of element X and gmatquant25 3 04 Jun 2013, 13:46
3 150 ml of 30% sulphuric acid was added antoxavier 5 21 Feb 2013, 21:14
5 Experts publish their posts in the topic There are three vessels of equal capacity .Vessel A contains Milk and gmatcracker24 11 10 Oct 2011, 03:09
5 How much pure alcohol should be added to 400ml of a 15% solu kirankp 6 02 Dec 2009, 00:21
Display posts from previous: Sort by

A vessel has 300 ml of pure milk. 30 ml of milk is removed and 30 ml

  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®.