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.

It appears that you are browsing the GMAT Club forum unregistered!

Signing up is free, quick, and confidential.
Join other 500,000 members and get the full benefits of GMAT Club

Registration gives you:

Tests

Take 11 tests and quizzes from GMAT Club and leading GMAT prep companies such as Manhattan GMAT,
Knewton, and others. All are free for GMAT Club members.

Applicant Stats

View detailed applicant stats such as GPA, GMAT score, work experience, location, application
status, and more

Books/Downloads

Download thousands of study notes,
question collections, GMAT Club’s
Grammar and Math books.
All are free!

Thank you for using the timer!
We noticed you are actually not timing your practice. Click the START button first next time you use the timer.
There are many benefits to timing your practice, including:

Two different solutions of alcohol with respective proportio [#permalink]

Show Tags

13 Aug 2009, 15:12

8

This post was BOOKMARKED

00:00

A

B

C

D

E

Difficulty:

(N/A)

Question Stats:

79% (03:01) correct
21% (01:43) wrong based on 19 sessions

HideShow timer Statistics

Two different solutions of alcohol with respective proportions of alcohol to water of 3:1 and 2:3 were combined. What is the concentration of alcohol in the new solution if the first solution was 4 times the amount of the second solution?
_________________

Re: Two different solutions of alcohol [#permalink]

Show Tags

13 Aug 2009, 15:19

5

This post received KUDOS

1

This post was BOOKMARKED

tejal777 wrote:

Two different solutions of alcohol with respective proportions of alcohol to water of 3:1 and 2:3 were combined. What is the concentration of alcohol in the new solution if the first solution was 4 times the amount of the second solution?

Detailed explanations please!

SOL: Lets assume that 40L of sol1 was mixed with 10L of sol2.

Alcohol in Sol1: 40*3/4 = 30L Alcohol in Sol2: 10*2/5 = 4L

Total Alcohol in the mixed solution of 50L = 30 + 4 = 34L

Alcohol concentration in the new sol: (34/50)*100 = 68%
_________________

Re: Two different solutions of alcohol [#permalink]

Show Tags

15 Aug 2009, 02:35

Good strategy by samrus. A slightly different way using variables:

Let sol1 have x liters, and sol2 have y liters. The ratio of alcohol to water in the final solution will be : [ (3/4)*x + (2/5)*y ] / [ (1/4)*x + (3/5)*y ]

Now, x=4y, substituting x in the above ratio, we get 17/8 as the ratio of alcohol to water in the final solution. Hence, concentration of alcohol is (17/25)*100 % = 68%

Re: Two different solutions of alcohol [#permalink]

Show Tags

16 Apr 2010, 16:36

A different approach: Alcohol in soln1 = 3/4 and in soln2 = 2/5 Using Alligation: 3/4--------?--2/5 4 : 1 So the resultant ratio (the ?) is at a 1/5th distance from 3/4 (or conversely at a 4/5th distance from 2/5. 3/4 - 2/5 = 7/20 Now, calculating 1/5th of 7/20 and subtracting it from 3/4 (3/4) - (1*5)/(7*20) = 75/100 - 7/100 = 68/100 = 68%

This approach is not quite advisable in this particular problem unless one is instinctive wrt alligation, but definitely awfully handy in other scenarios. This is just to enlighten people towards proper understanding of Alligation _________________

In a Normal Distribution, only the Average'Stand Out'

Re: Two different solutions of alcohol [#permalink]

Show Tags

11 Dec 2011, 09:57

2

This post received KUDOS

Second solution = 20 Thus first solution = 80 New solution (20+80) = 100

Alcohol in first solution = 80*3/4 = 60 Alcohol in second solution = 20*2/5 = 8 Total Alcohol = 68 Concentration of Alcohol 68/100*100= 68% Ans.
_________________

Re: Two different solutions of alcohol [#permalink]

Show Tags

01 Jun 2014, 23:11

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.
_________________

Re: Two different solutions of alcohol with respective proportio [#permalink]

Show Tags

10 Sep 2014, 13:11

tejal777 wrote:

Two different solutions of alcohol with respective proportions of alcohol to water of 3:1 and 2:3 were combined. What is the concentration of alcohol in the new solution if the first solution was 4 times the amount of the second solution?

Re: Two different solutions of alcohol with respective proportio [#permalink]

Show Tags

01 Sep 2016, 04:05

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.
_________________

Two different solutions of alcohol with respective proportio [#permalink]

Show Tags

01 Sep 2016, 09:10

Two different solutions of alcohol with respective proportions of alcohol to water of 3:1 and 2:3 were combined. What is the concentration of alcohol in the new solution if the first solution was 4 times the amount of the second solution?

let x=% of alcohol in new solution 3/4*4+2/5=5x x=68%

Re: Two different solutions of alcohol with respective proportio [#permalink]

Show Tags

11 Sep 2016, 22:55

2

This post received KUDOS

Can someone help to explain why solving the question as below didnt give OA? x: the proportion of alcohol to water of new solution (x-2/3)/(3-x)=4 15x=38 x=38/15 =>> the concentration of alcohol in the new solution is 38/(38+15)=38/53??

Thank you in advance!!!

gmatclubot

Re: Two different solutions of alcohol with respective proportio
[#permalink]
11 Sep 2016, 22:55

It’s quickly approaching two years since I last wrote anything on this blog. A lot has happened since then. When I last posted, I had just gotten back from...

Since my last post, I’ve got the interview decisions for the other two business schools I applied to: Denied by Wharton and Invited to Interview with Stanford. It all...