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

It is currently 22 Oct 2018, 12:24

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

A can contains a mixture of two liquids A & B in

  post reply Question banks Downloads My Bookmarks Reviews Important topics  
Author Message
Manager
Manager
avatar
Joined: 13 Apr 2006
Posts: 56
A can contains a mixture of two liquids A & B in  [#permalink]

Show Tags

New post 04 May 2006, 09:58
A can contains a mixture of two liquids A & B in proportion 7:5. When 9 litres of mixture is drawn off and the can is filled with liquid B, the proportion of A & B becomes 7:9. How many litres of liquid A was contained by the can initially?

A. 25
B. 10
C. 20
D. 21
E. 22

Please show your work.

--== Message from the GMAT Club Team ==--

THERE IS LIKELY A BETTER DISCUSSION OF THIS EXACT QUESTION.
This discussion does not meet community quality standards. It has been retired.


If you would like to discuss this question please re-post it in the respective forum. Thank you!

To review the GMAT Club's Forums Posting Guidelines, please follow these links: Quantitative | Verbal Please note - we may remove posts that do not follow our posting guidelines. Thank you.
Intern
Intern
avatar
Joined: 02 Feb 2006
Posts: 2
Good Problem  [#permalink]

Show Tags

New post 04 May 2006, 10:26
1
Answer is D

X/Y=7/5 - RATIO OF A to B
5X-7Y=0......(1)

9 litres would have : 7/12*9=5.25 of A and 9-5.25=3.75 of B

New ratio: (X-5.25)/(Y-3.75+9)=7/9
9X-7Y=16*5.25 ....... (2)

Solve eq 1 and 2 : answer is 21 for x
Manager
Manager
avatar
Joined: 13 Apr 2006
Posts: 56
  [#permalink]

Show Tags

New post 04 May 2006, 10:38
Great answer, thanks for simplifying
Manager
Manager
avatar
Joined: 13 Apr 2006
Posts: 56
  [#permalink]

Show Tags

New post 04 May 2006, 10:43
anyone else have another way to solve?
Director
Director
avatar
Joined: 16 Aug 2005
Posts: 922
Location: France
  [#permalink]

Show Tags

New post 04 May 2006, 10:47
A:B = 7:5

Total = 12 units

When 9 litres of mixture is removed, ((7/12) * 9) litres of A is removed, and ((5/12) * 9) litres of B is removed

Then 9 litres of B is added so that new ratio is 7:9

In new mixture, Total volume of A is 7x - ((7/12) * 9) = 7x - 21/4
And total volume of B is 5x - ((5/12) * 9) + 9 = 5x - 3 3/4 + 9 = 5x + 21/4

So, (7x - 21/4)/(5x + 21/4) = 7/9

Solving for x:
x=3
Original Volume of A = 7x = 21

Answer is D
Director
Director
avatar
Joined: 24 Oct 2005
Posts: 635
Location: London
  [#permalink]

Show Tags

New post 05 May 2006, 04:06
Initial proportion of A = (7/12) T
where T is the total.

9 litres taken away, the ratio of A becomes (7/16) of the total

ie. A =(7/16)(T-9)

(7/12)T = (7/16)(T-9)
Therefore, T = 36.

Initial proprtion of A = (7/12)(36) = 21

--== Message from the GMAT Club Team ==--

THERE IS LIKELY A BETTER DISCUSSION OF THIS EXACT QUESTION.
This discussion does not meet community quality standards. It has been retired.


If you would like to discuss this question please re-post it in the respective forum. Thank you!

To review the GMAT Club's Forums Posting Guidelines, please follow these links: Quantitative | Verbal Please note - we may remove posts that do not follow our posting guidelines. Thank you.
Non-Human User
User avatar
Joined: 09 Sep 2013
Posts: 8536
Premium Member
Re: A can contains a mixture of two liquids A & B in  [#permalink]

Show Tags

New post 28 Sep 2018, 22:16
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

GMAT Club Bot
Re: A can contains a mixture of two liquids A & B in &nbs [#permalink] 28 Sep 2018, 22:16
Display posts from previous: Sort by

A can contains a mixture of two liquids A & B in

  post reply Question banks Downloads My Bookmarks Reviews Important topics  

Moderator: chetan2u



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®.