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

It is currently 18 Oct 2019, 21:32

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

How many gallons of milk that is 10 percent butter-fat must

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

Hide Tags

Find Similar Topics 
Director
Director
avatar
Joined: 29 Nov 2012
Posts: 697
How many gallons of milk that is 10 percent butter-fat must  [#permalink]

Show Tags

New post 03 Sep 2013, 06:35
6
4
00:00
A
B
C
D
E

Difficulty:

  15% (low)

Question Stats:

84% (01:49) correct 16% (02:09) wrong based on 268 sessions

HideShow timer Statistics

How many gallons of milk that is 10 percent butter-fat must be added to 8 gallons of milk that is 35 percent butterfat to obtain milk that is 20 percent butterfat?

a) 6
b) 12
c) 14
d) 16
e) 28

Please provide detailed explanations!
Most Helpful Expert Reply
Math Expert
User avatar
V
Joined: 02 Sep 2009
Posts: 58453
Re: How many gallons of milk that is 10 percent butter-fat must  [#permalink]

Show Tags

New post 03 Sep 2013, 06:39
5
1
General Discussion
Director
Director
avatar
Joined: 29 Nov 2012
Posts: 697
Re: How many gallons of milk that is 10 percent butter-fat must  [#permalink]

Show Tags

New post 03 Sep 2013, 06:44
I Messed up the equations. Thanks for the quick reply!
Manager
Manager
avatar
Joined: 23 May 2013
Posts: 93
GMAT ToolKit User
Re: How many gallons of milk that is 10 percent butter-fat must  [#permalink]

Show Tags

New post 19 Jan 2014, 06:30
would this be a 600-700 question?
_________________
“Confidence comes not from always being right but from not fearing to be wrong.”
Math Expert
User avatar
V
Joined: 02 Sep 2009
Posts: 58453
Re: How many gallons of milk that is 10 percent butter-fat must  [#permalink]

Show Tags

New post 19 Jan 2014, 09:55
Intern
Intern
avatar
Joined: 22 Jan 2014
Posts: 3
Re: How many gallons of milk that is 10 percent butter-fat must  [#permalink]

Show Tags

New post 24 Jan 2014, 08:03
Bunuel wrote:
fozzzy wrote:
How many gallons of milk that is 10 percent butter-fat must be added to 8 gallons of milk that is 35 percent butterfat to obtain milk that is 20 percent butterfat?

a) 6
b) 12
c) 14
d) 16
e) 28

Please provide detailed explanations!


Equate the fat:

0.1x + 0.35*8 = 0.2(x + 8) --> x = 12.

Answer: B.


Thanks. This is so easy with these equations! I was trying to solve this using weighted averages formula and end up with 15:10 = 8:x => x = 4/3 How can this be solved using the weighted average formula?
Intern
Intern
avatar
Joined: 05 Feb 2014
Posts: 40
Re: How many gallons of milk that is 10 percent butter-fat must  [#permalink]

Show Tags

New post 09 May 2014, 12:23
2
For guys looking to solve by allegation

10% ............... 35%

........... 20% ..........

15% ................ 10%


\(15/10 = 3/2\) ->> \(3/2 * 8 = 12\)
Senior Manager
Senior Manager
User avatar
Status: The Final Countdown
Joined: 07 Mar 2013
Posts: 280
Concentration: Technology, General Management
GMAT 1: 710 Q47 V41
GPA: 3.84
WE: Information Technology (Computer Software)
Re: How many gallons of milk that is 10 percent butter-fat must  [#permalink]

Show Tags

New post 15 Dec 2014, 05:17
Where can allegation concepts be learnt?It seems easier and faster than setting up equations..
Director
Director
User avatar
G
Joined: 23 Jan 2013
Posts: 525
Schools: Cambridge'16
Re: How many gallons of milk that is 10 percent butter-fat must  [#permalink]

Show Tags

New post 14 Mar 2015, 03:53
10%-------------20%-----------35%

10x=15*8

10x=120 => x=12

B
CEO
CEO
User avatar
D
Status: GMATINSIGHT Tutor
Joined: 08 Jul 2010
Posts: 2978
Location: India
GMAT: INSIGHT
Schools: Darden '21
WE: Education (Education)
Reviews Badge
Re: How many gallons of milk that is 10 percent butter-fat must  [#permalink]

Show Tags

New post 29 Aug 2016, 10:53
fozzzy wrote:
How many gallons of milk that is 10 percent butter-fat must be added to 8 gallons of milk that is 35 percent butterfat to obtain milk that is 20 percent butterfat?

a) 6
b) 12
c) 14
d) 16
e) 28

Please provide detailed explanations!


Fat of First Solution + Fat of second Solution = Fat of Final Mixture

(10/100)*x + (35/100)*8 = (20/100)*(x+8)

i.e. 10x + 280 = 20x + 160

i.e. 10x = 120

i.e. x = 12

Answer: Option B
_________________
Prosper!!!
GMATinsight
Bhoopendra Singh and Dr.Sushma Jha
e-mail: info@GMATinsight.com I Call us : +91-9999687183 / 9891333772
Online One-on-One Skype based classes and Classroom Coaching in South and West Delhi
http://www.GMATinsight.com/testimonials.html

ACCESS FREE GMAT TESTS HERE:22 ONLINE FREE (FULL LENGTH) GMAT CAT (PRACTICE TESTS) LINK COLLECTION
GMAT Club Legend
GMAT Club Legend
User avatar
V
Joined: 12 Sep 2015
Posts: 4009
Location: Canada
Re: How many gallons of milk that is 10 percent butter-fat must  [#permalink]

Show Tags

New post 20 Mar 2018, 08:14
1
Top Contributor
fozzzy wrote:
How many gallons of milk that is 10 percent butter-fat must be added to 8 gallons of milk that is 35 percent butterfat to obtain milk that is 20 percent butterfat?

a) 6
b) 12
c) 14
d) 16
e) 28


One option is to focus on the butter fat

We begin with 8 gallons of milk that is 35 percent butter-fat
So, the volume of butter fat = 35% of 8
= (0.35)(8)
= 2.8 gallons of butter fat (to begin)

Let x = number of gallons of milk that is 10 percent butter-fat to be added to the initial 8 gallons
The volume of butter fat = 10% of x
= 0.1x gallons of butter fat (to be added)

So, in the RESULTING mixture, we have:
Total volume of butter fat = 2.8 + 0.1x
TOTAL VOLUME of mixture = 8 + x

We want the RESULTING mixture to be 20 percent butter-fat
In other words, we want: (Total volume of butter fat)/(TOTAL VOLUME of mixture) = 20%
We can now write: (2.8 + 0.1x)/(8 + x) = 20/100
Cross multiply to get: 100(2.8 + 0.1x) = 20(8 + x)
Expand: 280 + 10x = 160 + 20x
Rearrange: 120 = 10x
Solve: x = 12

Answer: B

RELATED VIDEO

_________________
Test confidently with gmatprepnow.com
Image
Target Test Prep Representative
User avatar
G
Status: Head GMAT Instructor
Affiliations: Target Test Prep
Joined: 04 Mar 2011
Posts: 2815
Re: How many gallons of milk that is 10 percent butter-fat must  [#permalink]

Show Tags

New post 21 Mar 2018, 16:19
fozzzy wrote:
How many gallons of milk that is 10 percent butter-fat must be added to 8 gallons of milk that is 35 percent butterfat to obtain milk that is 20 percent butterfat?

a) 6
b) 12
c) 14
d) 16
e) 28


We add x gallons of 10% butterfat milk to 8 gallons of 35% butterfat milk, and we obtain (x + 8) gallons of 20% butterfat milk. We can express this in an equation as:

0.1x + 0.35(8) = 0.2(x + 8)

0.1x + 2.8 = 0.2x + 1.6

1.2 = 0.1x

12 = x

Answer: B
_________________

Jeffrey Miller

Head of GMAT Instruction

Jeff@TargetTestPrep.com
TTP - Target Test Prep Logo
122 Reviews

5-star rated online GMAT quant
self study course

See why Target Test Prep is the top rated GMAT quant course on GMAT Club. Read Our Reviews

If you find one of my posts helpful, please take a moment to click on the "Kudos" button.

Non-Human User
User avatar
Joined: 09 Sep 2013
Posts: 13264
Re: How many gallons of milk that is 10 percent butter-fat must  [#permalink]

Show Tags

New post 25 Jul 2019, 05:55
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 Club Bot
Re: How many gallons of milk that is 10 percent butter-fat must   [#permalink] 25 Jul 2019, 05:55
Display posts from previous: Sort by

How many gallons of milk that is 10 percent butter-fat must

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





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