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

It is currently 25 Aug 2016, 01:21
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 certain shade of gray paint is obtained by mixing 3 parts

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

Hide Tags

3 KUDOS received
Intern
Intern
avatar
Joined: 19 Apr 2010
Posts: 1
Followers: 0

Kudos [?]: 20 [3] , given: 1

GMAT ToolKit User
A certain shade of gray paint is obtained by mixing 3 parts [#permalink]

Show Tags

New post 29 May 2010, 13:11
3
This post received
KUDOS
14
This post was
BOOKMARKED
00:00
A
B
C
D
E

Difficulty:

  65% (hard)

Question Stats:

56% (02:29) correct 44% (01:51) wrong based on 466 sessions

HideShow timer Statistics

A certain shade of gray paint is obtained by mixing 3 parts of white paint with 5 parts of black paint. If 2 gallons of the mixture is needed and the individual colors can be purchased only in one gallon or half gallon cans, what is the least amount of paint, in gallons, that must be purchased in order to measure out the portions needed for the mixture?

A. 2
B. 2 1/2
C. 3
D. 3 1/2
E. 4
[Reveal] Spoiler: OA

Last edited by Bunuel on 13 Jun 2013, 02:18, edited 2 times in total.
Added the OA
Expert Post
17 KUDOS received
Math Expert
User avatar
Joined: 02 Sep 2009
Posts: 34423
Followers: 6252

Kudos [?]: 79429 [17] , given: 10016

Re: Pease help [#permalink]

Show Tags

New post 29 May 2010, 13:34
17
This post received
KUDOS
Expert's post
2
This post was
BOOKMARKED
overlord168 wrote:
A certain shade of gray paint is obtained by mixing 3 parts of white paint with 5 parts of black paint. If 2 gallons of the mixture is needed and the individual colors can be purchased only in one gallon or half gallon cans, what is the least amount of paint, in gallons, that must be purchased in order to measure out the portions needed for the mixture?

a. 2
b. 2 1/2
c. 3
d 3 1/2
e. 4


2 gallon of gray paint needs \(2*\frac{3}{3+5}=2*\frac{3}{8}=\frac{3}{4}\) gallons of white paint and \(2*\frac{5}{8}=\frac{5}{4}\) gallons of black paint.

To get \(\frac{3}{4}=0.75\) gallons of white paint we should purchase at least 1 gallon of white paint;
To get \(\frac{5}{4}=1.25\) gallons of black paint we should purchase at least 1.5 gallons of black paint.

Total: 1+1.5=2.5.

Answer: B.

Hope it helps.
_________________

New to the Math Forum?
Please read this: 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

Manager
Manager
avatar
Joined: 20 Apr 2010
Posts: 153
Location: I N D I A
Followers: 3

Kudos [?]: 19 [0], given: 16

Re: Pease help [#permalink]

Show Tags

New post 01 Jun 2010, 02:43
Doesn't 3 parts of white paint with 5 parts of black paint. play any role... plzz explain..im missing somewhere..

thanks
Expert Post
4 KUDOS received
Math Expert
User avatar
Joined: 02 Sep 2009
Posts: 34423
Followers: 6252

Kudos [?]: 79429 [4] , given: 10016

Re: Pease help [#permalink]

Show Tags

New post 01 Jun 2010, 04:10
4
This post received
KUDOS
Expert's post
sag wrote:
Doesn't 3 parts of white paint with 5 parts of black paint. play any role... plzz explain..im missing somewhere..

thanks


Gray paint is obtained by mixing 3 parts of white paint with 5 parts of black paint --> total 8 parts --> white 3/8 and black 5/8 --> 2 gallon of gray paint needs \(2*\frac{3}{8}=\frac{3}{4}\) gallons of white paint and \(2*\frac{5}{8}=\frac{5}{4}\) gallons of black paint.

Hope it's clear now.
_________________

New to the Math Forum?
Please read this: 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

Manager
Manager
avatar
Joined: 20 Apr 2010
Posts: 153
Location: I N D I A
Followers: 3

Kudos [?]: 19 [0], given: 16

Re: Pease help [#permalink]

Show Tags

New post 01 Jun 2010, 07:08
Thanks Bunuel.. Its crystal clear now.. now even ur 1st ans to this Q explains everything very clearly...
Thanks once again... +1...
1 KUDOS received
VP
VP
avatar
Joined: 05 Mar 2008
Posts: 1473
Followers: 11

Kudos [?]: 253 [1] , given: 31

Re: Mixture Problem [#permalink]

Show Tags

New post 22 Jul 2010, 08:49
1
This post received
KUDOS
1
This post was
BOOKMARKED
TheSituation wrote:
I've been banging my head against the wall on this one... someone please give me a simple straightforward solution and assurance that it was a very difficult question lol.

A certain shade of gray paint is obtained by mixing 3 parts of white paint with 5 parts of black paint. If 2 gallons of the mixture is needed and the individual colors can be purchased only in one-gallon or half- gallon cans, what is the least amount of paint, in gallons, that must be purchased in order to measure out the portions needed for the mixture?
(A) 2
(B) 2.5
(C) 3
(D) 3.5
(E) 4

OA:
[Reveal] Spoiler:
B


white = 3/8
black = 5/8

Combine both and that equals 1 gallon

Multiply each by two to get 2 gallons

(3/8)*2 + (5/8)*2 = 2

(3/8)*2 = 6/8 = 3/4 = .75
(5/8)*2 = 10/8 = 5/4 = 1.25

You need .75 gallons of white but since it comes in 1/2 or 1 you need 1 gallon
You need 1.25 gallons of black but since it comes in 1/2 or 1 you need 1.5

1+1.5 = 2.5
Expert Post
2 KUDOS received
Math Expert
User avatar
Joined: 02 Sep 2009
Posts: 34423
Followers: 6252

Kudos [?]: 79429 [2] , given: 10016

Re: A certain shade of gray paint is obtained by mixing 3 parts [#permalink]

Show Tags

New post 13 Jun 2013, 03:09
2
This post received
KUDOS
Expert's post
Intern
Intern
avatar
Joined: 29 May 2013
Posts: 7
Followers: 0

Kudos [?]: 1 [0], given: 3

Re: A certain shade of gray paint is obtained by mixing 3 parts [#permalink]

Show Tags

New post 30 Jun 2013, 09:25
Let one gallon be 80 liters. ( Assume smartly)

30 White +50 black = 80liters

According 2 question, we need 2 gallons i.e- 160 liters. ( multiply above equation with 2)

60W+100B=160 ltrs

Minimum gallons for 60W=1 ( 1 gallon =80 liters, 1/2=40 liters)
Minimum gallons for (80+20) B= 1+0.5=1.5
Total = 1+1.5=2.5

Ans. 2.5
Intern
Intern
avatar
Joined: 07 Oct 2012
Posts: 23
Location: India
Concentration: General Management, Finance
GMAT 1: 640 Q45 V33
WE: Engineering (Other)
Followers: 0

Kudos [?]: 11 [0], given: 7

Re: A certain shade of gray paint is obtained by mixing 3 parts [#permalink]

Show Tags

New post 13 Jul 2013, 23:20
Given W:B = 3:5
That means say 3 gallons of white paint + 5 gallons of black paint = 8 gallons of paint mixture.
But we want least amount of white & black paints for minimum of 2 gallons of mixture, so lets reduce keeping same ratio,
1.5 : 2.5 gives 1.5 + 2.5 = 4 gallons of mixture, but we want only 2 gallons, lets further reduce
0.75: 1.25 gives 1+1.5 = 2.5 gallons of mixture. This looks ok, but lets reduce further just to be sure
0.375: 0.625 gives 0.5 + 1 = 1.5 gallons of mixture, thats less than 2 gallons of mixture, so not acceptable.
So correct ans is 2.5 gallons. B
Manager
Manager
avatar
Joined: 07 Dec 2009
Posts: 110
GMAT Date: 12-03-2014
Followers: 0

Kudos [?]: 24 [0], given: 367

GMAT ToolKit User Premium Member
Re: A certain shade of gray paint is obtained by mixing 3 parts [#permalink]

Show Tags

New post 02 Aug 2014, 09:16
The mixture is made up of 3 parts white paint and 5 parts Black paint.
Hence total is 8 parts make 2 gallons of mixture.
8x = 2(gallons) ==> x = 1/4

White paint needed = 3* 1/4 =0.75. Minimum White paint needed = 1
Black Paint needed = 5* 1/4 = 1.25 Minimum Black Paint needed = 1.5

Hence Answer = 2.5. B
Intern
Intern
avatar
Joined: 25 Mar 2014
Posts: 33
Followers: 0

Kudos [?]: 40 [0], given: 38

Re: A certain shade of gray paint is obtained by mixing 3 parts [#permalink]

Show Tags

New post 25 Nov 2014, 06:48
[...]in order to measure out the portions needed for the mixture?

How can you measure 0,75 gallons if you have only buckets of 0,5 and 1 gallons?

My answer:
2 cans of 1 gallon and 1 half can of black
1 can and a half of white
result: 4 gallons!

Unless you have an other bottle (or any thing to measure), you cannot separate 0,75 gallons!
Bunuel
Expert Post
Math Expert
User avatar
Joined: 02 Sep 2009
Posts: 34423
Followers: 6252

Kudos [?]: 79429 [0], given: 10016

Re: A certain shade of gray paint is obtained by mixing 3 parts [#permalink]

Show Tags

New post 25 Nov 2014, 07:03
plaverbach wrote:
[...]in order to measure out the portions needed for the mixture?

How can you measure 0,75 gallons if you have only buckets of 0,5 and 1 gallons?

My answer:
2 cans of 1 gallon and 1 half can of black
1 can and a half of white
result: 4 gallons!

Unless you have an other bottle (or any thing to measure), you cannot separate 0,75 gallons!
Bunuel


Please re-read the solution.

To get 2 gallons of gray paint we need \(\frac{3}{4}\) gallons of white paint and \(\frac{5}{4}\) gallons of black paint.

To get \(\frac{3}{4}=0.75\) gallons of white paint we should purchase at least 1 gallon of white paint;
To get \(\frac{5}{4}=1.25\) gallons of black paint we should purchase at least 1.5 gallons of black paint.

Total: 1+1.5=2.5.

Answer: B.
_________________

New to the Math Forum?
Please read this: 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

GMAT Club Legend
GMAT Club Legend
User avatar
Joined: 09 Sep 2013
Posts: 11044
Followers: 509

Kudos [?]: 134 [0], given: 0

Premium Member
Re: A certain shade of gray paint is obtained by mixing 3 parts [#permalink]

Show Tags

New post 11 Jan 2016, 10:13
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 certain shade of gray paint is obtained by mixing 3 parts   [#permalink] 11 Jan 2016, 10:13
    Similar topics Author Replies Last post
Similar
Topics:
10 Experts publish their posts in the topic To create paint with a certain shade of gray, one must combine 2.016 Bunuel 6 23 Mar 2015, 06:30
Experts publish their posts in the topic At Deluxe paint store, Fuchsia paint is made by mixing 5 parts of red aparnaharish 7 10 Aug 2013, 02:57
1 Experts publish their posts in the topic A certain drink of type A is prepared by mixing 4 parts milk with 3 pa aselfmademan 10 31 Oct 2011, 02:15
A shade of paint is made by evenly mixing m gallons of white bmwhype2 5 24 Nov 2007, 02:15
6 Experts publish their posts in the topic A certain shade of gray paint is obtained by mixing 3 parts auniyal 12 12 Feb 2007, 09:32
Display posts from previous: Sort by

A certain shade of gray paint is obtained by mixing 3 parts

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


GMAT Club MBA Forum Home| About| 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®.