Summer is Coming! Join the Game of Timers Competition to Win Epic Prizes. Registration is Open. Game starts Mon July 1st.

It is currently 20 Jul 2019, 00:48

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

What amount (in milliliters) of a 1% sulfuric acid solution must be ad

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

Hide Tags

Find Similar Topics 
Math Expert
User avatar
V
Joined: 02 Sep 2009
Posts: 56300
What amount (in milliliters) of a 1% sulfuric acid solution must be ad  [#permalink]

Show Tags

New post 29 Mar 2018, 00:25
00:00
A
B
C
D
E

Difficulty:

  25% (medium)

Question Stats:

74% (01:38) correct 26% (02:01) wrong based on 160 sessions

HideShow timer Statistics


Senior PS Moderator
User avatar
D
Status: It always seems impossible until it's done.
Joined: 16 Sep 2016
Posts: 751
GMAT 1: 740 Q50 V40
GMAT 2: 770 Q51 V42
GMAT ToolKit User Reviews Badge
Re: What amount (in milliliters) of a 1% sulfuric acid solution must be ad  [#permalink]

Show Tags

New post 29 Mar 2018, 01:27
1
1
Bunuel wrote:
What amount (in milliliters) of a 1% sulfuric acid solution must be added to 60 milliliters of a 6% sulfuric acid solution to yield a 5% sulfuric acid solution?

(A) 12
(B) 15
(C) 18
(D) 20
(E) 45


60 ml 6% sulphuric acid has \(\frac{6}{100}*60 = 3.6\) ml sulphuric acid and rest is water.

x ml of 1% sulphuric acid will have \(\frac{1}{100}*x = x/100\) ml of sulphuric acid.

so total sulphuric acid will be 3.6 + x/100 in total volume of 60 + x.

This new mixture has to be 5% sulphuric acid

Hence 5% of (60+x) = 3.6 + x/100

\(\frac{5}{100}*(60 + x) = 3.6 + \frac{x}{100}\)
\(3 + \frac{5x}{100} = 3.6 + \frac{x}{100}\)
\(\frac{4x}{100} = 0.6\)
\(x = \frac{60}{4}\)
\(x = 15\) ml

Hence Option (B) is our answer.

Best,
Gladi
_________________
Regards,
Gladi



“Do. Or do not. There is no try.” - Yoda (The Empire Strikes Back)
CEO
CEO
User avatar
D
Status: GMATINSIGHT Tutor
Joined: 08 Jul 2010
Posts: 2959
Location: India
GMAT: INSIGHT
Schools: Darden '21
WE: Education (Education)
Reviews Badge
Re: What amount (in milliliters) of a 1% sulfuric acid solution must be ad  [#permalink]

Show Tags

New post 29 Mar 2018, 03:33
1
Bunuel wrote:
What amount (in milliliters) of a 1% sulfuric acid solution must be added to 60 milliliters of a 6% sulfuric acid solution to yield a 5% sulfuric acid solution?

(A) 12
(B) 15
(C) 18
(D) 20
(E) 45


TIP: For all such questions of Mixtures one must make an equation of actual quantity of one substance.

For instance here the equation can be formed on the quantity of sulfuric acid

Sulfuric acid of 60 ml solution + Sulfuric acid of 1% solution = Sulfuric acid of Final solution

i.e. (6/100)*60 + (1/100)*x = (5/100)*(60+x)

i.e. x = 15

Answer: Option B

Alternatively: One may use allegation method however I suggest that for starters and not so strong in maths should follow the method of making equation
_________________
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
Retired Moderator
User avatar
V
Joined: 27 Oct 2017
Posts: 1231
Location: India
Concentration: International Business, General Management
GPA: 3.64
WE: Business Development (Energy and Utilities)
Re: What amount (in milliliters) of a 1% sulfuric acid solution must be ad  [#permalink]

Show Tags

New post 29 Mar 2018, 04:13
The best approach shall be using principle of alligation.

Principle: If two ingredients A and B of price x and y respectively are mixed and the price of resultant mixture is M (mean price)then the ratio (R) in which ingredients are mixed is given by, the rule of allegation

R=(M−y)/(x−M)

Posted from my mobile device

Posted from my mobile device
_________________
Retired Moderator
User avatar
V
Joined: 27 Oct 2017
Posts: 1231
Location: India
Concentration: International Business, General Management
GPA: 3.64
WE: Business Development (Energy and Utilities)
Re: What amount (in milliliters) of a 1% sulfuric acid solution must be ad  [#permalink]

Show Tags

New post 29 Mar 2018, 04:17
2
Please see the sketch for alligation approach

gmatbusters wrote:
The best approach shall be using principle of alligation.

Principle: If two ingredients A and B of price x and y respectively are mixed and the price of resultant mixture is M (mean price)then the ratio (R) in which ingredients are mixed is given by, the rule of allegation

R=(M−y)/(x−M)

Posted from my mobile device

Posted from my mobile device

Attachments

IMG_20180329_163830.jpg
IMG_20180329_163830.jpg [ 495.3 KiB | Viewed 1663 times ]


_________________
VP
VP
avatar
P
Joined: 07 Dec 2014
Posts: 1207
What amount (in milliliters) of a 1% sulfuric acid solution must be ad  [#permalink]

Show Tags

New post 29 Mar 2018, 10:01
Bunuel wrote:
What amount (in milliliters) of a 1% sulfuric acid solution must be added to 60 milliliters of a 6% sulfuric acid solution to yield a 5% sulfuric acid solution?

(A) 12
(B) 15
(C) 18
(D) 20
(E) 45


let x=amount of 1% acid to be added
.01*x+.06*60=.05(60+x)
x=15 milliliters
B
Target Test Prep Representative
User avatar
D
Status: Founder & CEO
Affiliations: Target Test Prep
Joined: 14 Oct 2015
Posts: 6968
Location: United States (CA)
Re: What amount (in milliliters) of a 1% sulfuric acid solution must be ad  [#permalink]

Show Tags

New post 30 Mar 2018, 10:47
Bunuel wrote:
What amount (in milliliters) of a 1% sulfuric acid solution must be added to 60 milliliters of a 6% sulfuric acid solution to yield a 5% sulfuric acid solution?

(A) 12
(B) 15
(C) 18
(D) 20
(E) 45


We can let the amount of 1% sulfuric acid to be added = n and create the equation:

(0.01n + 0.06 x 60)/(60 + n) = 0.05

0.01n + 3.6 = 0.05(60 + n)

0.01n + 3.6 = 3 + 0.05n

0.6 = 0.04n

15 = n

Answer: B
_________________

Scott Woodbury-Stewart

Founder and CEO

Scott@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.

Senior SC Moderator
avatar
V
Joined: 22 May 2016
Posts: 3087
What amount (in milliliters) of a 1% sulfuric acid solution must be ad  [#permalink]

Show Tags

New post 31 Mar 2018, 11:38
Bunuel wrote:
What amount (in milliliters) of a 1% sulfuric acid solution must be added to 60 milliliters of a 6% sulfuric acid solution to yield a 5% sulfuric acid solution?

(A) 12
(B) 15
(C) 18
(D) 20
(E) 45

Let x = amount of 1% sulfuric acid to be added
A = solution with 1% sulfuric acid
B = solution with 6% sulfuric acid

(% A)(Vol A) + (% B)(Vol B) = (% of A+B)(Vol of A+B)

\(.01(x) + .06(60) = .05(x + 60)\)
Multiply all by 100 to make math quicker
\(1x + 6(60) = 5(x + 60)\)
\(1x + 360 = 5x + 300\)
\(4x = 60\)
\(x=\frac{60}{4}=15\)

Answer B
_________________
SC Butler has resumed!
Get two SC questions to practice, whose links you can find by date, here.

-- Take another look. Take a look around. These are the moments you can't pass by.
Intern
Intern
avatar
B
Joined: 10 Feb 2018
Posts: 21
Location: United States (TX)
Schools: McCombs '21 (WA)
GMAT 1: 690 Q40 V44
GPA: 3.58
WE: Project Management (Computer Software)
Re: What amount (in milliliters) of a 1% sulfuric acid solution must be ad  [#permalink]

Show Tags

New post 22 Jul 2018, 20:13
Bunuel wrote:
What amount (in milliliters) of a 1% sulfuric acid solution must be added to 60 milliliters of a 6% sulfuric acid solution to yield a 5% sulfuric acid solution?

(A) 12
(B) 15
(C) 18
(D) 20
(E) 45


6% solution: 6 --> 5 = 1
1% solution: 1 --> 5 = 4

Original amount = 60mL

Ratio 6%:1% = 4:1 = 4/1

Original amount / X = Ratio of 6%/1%

60/x = 4/1

x = 15mL
Intern
Intern
avatar
B
Joined: 08 Jul 2018
Posts: 8
Re: What amount (in milliliters) of a 1% sulfuric acid solution must be ad  [#permalink]

Show Tags

New post 16 Aug 2018, 11:30
0.06(60)+0.01x=0.05(60+x)
=> 0.04x=0.6
=>x=15
GMAT Club Bot
Re: What amount (in milliliters) of a 1% sulfuric acid solution must be ad   [#permalink] 16 Aug 2018, 11:30
Display posts from previous: Sort by

What amount (in milliliters) of a 1% sulfuric acid solution must be ad

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





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