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:

A tank contains 10,000 gallons of a solution that is 5 % [#permalink]

Show Tags

11 Oct 2005, 03:04

1

This post received KUDOS

3

This post was BOOKMARKED

00:00

A

B

C

D

E

Difficulty:

25% (medium)

Question Stats:

73% (02:08) correct
27% (01:22) wrong based on 491 sessions

HideShow timer Statistics

A tank contains 10,000 gallons of a solution that is 5 percent sodium chloride by volume. If 2,500 gallons of water evaporate from the tank, the remaining solution will be approximately what percent sodium chloride?

I think my brain evaporated, because I dont even get any of the solutions given...

A tank contains 10,000 gallons of a solution that is 5 percent sodium chloride by volume. If 2,500 gallons of water evaporate from the tank, the remaining solution will be approximately what percent sodium chloride?

(A) 1.25% (B) 3.75% (C) 6.25% (D) 6.67% (E) 11.7%

there're 5%*10,000(= 500 gallons) of NaCl in the solution
===> there're 9,500 (=10,000-500) gallons of water in the solution.
after 2,500 gallons of water evaporate, there's 7,000 gallons of water left ===> the percentage of NaCl is 500 gallons NaCl/ (500+7,000) ( this is the volume of the solution) *100%= 6,67% . It's D.

Original =10,000 ----> sodium chloride = 5% ie 500
New = 10,000-2,500 = 7500.

New % = (500/7500) * 100

= 6.67%

nero44 wrote:

I think my brain evaporated, because I dont even get any of the solutions given...

A tank contains 10,000 gallons of a solution that is 5 percent sodium chloride by volume. If 2,500 gallons of water evaporate from the tank, the remaining solution will be approximately what percent sodium chloride?

Re: A tank contains 10,000 gallons of a solution that is 5% [#permalink]

Show Tags

03 Mar 2012, 11:14

hi, everybody,

Sorry for raised this question again, but I a little bit confused with the question by itself.

Is that correct that if I interpret the question statement 'the remaining solution' (A) will be approximately what percent (B) 'sodium chloride'? as A=%B?

A tank contains 10,000 gallons of a solution that is 5 percent sodium chloride by volume. If 2,500 gallons of water evaporate from the tank, the remaining solution will be approximately what percent sodium chloride?

(A) 1.25% (B) 3.75% (C) 6.25% (D) 6.67% (E) 11.7%

hi, everybody,

Sorry for raised this question again, but I a little bit confused with the question by itself.

Is that correct that if I interpret the question statement 'the remaining solution' (A) will be approximately what percent (B) 'sodium chloride'? as A=%B?

It makes me generate wrong answer!

Thanks

"The remaining solution will be approximately what percent sodium chloride?" means: what percent of the remaining solution is sodium chloride. Now, since the remaining solution is 10,000-2,500=7,500 gallons and sodium chloride is 500 gallons (5% of initial solution of 10,000 gallons) then sodium chloride is 500/7,500*100=~6.66% of the remaining solution of 7,500 gallons.

Re: A tank contains 10,000 gallons of a solution that is 5 % [#permalink]

Show Tags

27 Mar 2012, 22:30

I'm really slow with math, need suggestions.

I solved this question in 2 minutes 45 seconds and got the correct answer, but obviously my time was too slow. Any suggestions for how to complete this quickly? The slowest part for me was calculating what 500/7500 is.

This was my process: 500/7500 = 5/75 = 1/15.

Long division 1/15 = 6.6% (then looked for correct answer).

Any suggestions for how to do that calculation faster (beyond just memorizing) would be great!

Re: A tank contains 10,000 gallons of a solution that is 5 % [#permalink]

Show Tags

02 Oct 2013, 14:33

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.
_________________

A tank contains 10,000 gallons of a solution that is 5 % [#permalink]

Show Tags

19 Jan 2015, 09:49

Hey,

I have two questions on this problem: 1) Saying that it is a "solution" we should assume that there are at least 2 elements in it? 2) Because it says 2500 gallons of water evaporated, we should assume that only water evaporated, so the sodium chloride has remained intact?

That because if you think that the solution is the "sodium chloride", then the % should remain the same (5%) after some amount of the solution is gone. Which would make you answer # B. Even though this is obiously wrong as the % would be the same..

It does make sense that you are supposed to understand that there are 2 elements in this solution, and sodium chloride has remained intact, since it was only water that evaporated, but I guess in this case they could have made it a bit more obvious by saying "If 2,500 gallons that consist only of water evaporate from the tank ", then you would get the correct answer quite easily...

Sorry, it just seems a bit ridiculous that they trick you for silly reasons..

Re: A tank contains 10,000 gallons of a solution that is 5 % [#permalink]

Show Tags

19 Jan 2015, 10:40

Bunuel wrote:

Minhphuoc wrote:

A tank contains 10,000 gallons of a solution that is 5 percent sodium chloride by volume. If 2,500 gallons of water evaporate from the tank, the remaining solution will be approximately what percent sodium chloride?

(A) 1.25% (B) 3.75% (C) 6.25% (D) 6.67% (E) 11.7%

hi, everybody,

Sorry for raised this question again, but I a little bit confused with the question by itself.

Is that correct that if I interpret the question statement 'the remaining solution' (A) will be approximately what percent (B) 'sodium chloride'? as A=%B?

It makes me generate wrong answer!

Thanks

"The remaining solution will be approximately what percent sodium chloride?" means: what percent of the remaining solution is sodium chloride. Now, since the remaining solution is 10,000-2,500=7,500 gallons and sodium chloride is 500 gallons (5% of initial solution of 10,000 gallons) then sodium chloride is 500/7,500*100=~6.66% of the remaining solution of 7,500 gallons.

As you said the question asks 'what percent of the remaining solution is sodium chloride'.

After evaporation,

volume of water=7500 gallons

volume of sodium chloride =500(no change)

total volume of the SOLUTION(water and sodium chloride)=7500+500

therfore 500/8000*100=6.25

Even though this does not match the right answer my doubt is why are you not taking the total which includes both? Initially we did take solution to be water and sodium chloride as one.The question uses the term 'remaining solution'. Could you please help me clear this confusion?

A tank contains 10,000 gallons of a solution that is 5 percent sodium chloride by volume. If 2,500 gallons of water evaporate from the tank, the remaining solution will be approximately what percent sodium chloride?

(A) 1.25% (B) 3.75% (C) 6.25% (D) 6.67% (E) 11.7%

hi, everybody,

Sorry for raised this question again, but I a little bit confused with the question by itself.

Is that correct that if I interpret the question statement 'the remaining solution' (A) will be approximately what percent (B) 'sodium chloride'? as A=%B?

It makes me generate wrong answer!

Thanks

"The remaining solution will be approximately what percent sodium chloride?" means: what percent of the remaining solution is sodium chloride. Now, since the remaining solution is 10,000-2,500=7,500 gallons and sodium chloride is 500 gallons (5% of initial solution of 10,000 gallons) then sodium chloride is 500/7,500*100=~6.66% of the remaining solution of 7,500 gallons.

As you said the question asks 'what percent of the remaining solution is sodium chloride'.

After evaporation,

volume of water=7500 gallons

volume of sodium chloride =500(no change)

total volume of the SOLUTION(water and sodium chloride)=7500+500

therfore 500/8000*100=6.25

Even though this does not match the right answer my doubt is why are you not taking the total which includes both? Initially we did take solution to be water and sodium chloride as one.The question uses the term 'remaining solution'. Could you please help me clear this confusion?

After 2,500 gallons of water evaporates from the tank, we are left with 7,500 gallons of solution, which includes 500 gallons of sodium chloride.
_________________

Re: A tank contains 10,000 gallons of a solution that is 5 % [#permalink]

Show Tags

22 Jul 2015, 21:27

nero44 wrote:

A tank contains 10,000 gallons of a solution that is 5 percent sodium chloride by volume. If 2,500 gallons of water evaporate from the tank, the remaining solution will be approximately what percent sodium chloride?

(A) 1.25% (B) 3.75% (C) 6.25% (D) 6.67% (E) 11.7%

I got confused with this question,i thought when water would evaporate so would sodium chloride, and if 2500 solution evaporates , then there would be some kind of proportion by which evaporation happens--eg 500:9500 , so i applied all the logic and then read the question and explanation...there was i Wrong ...Gmat can be very frustrating at time,,but fun too

Re: A tank contains 10,000 gallons of a solution that is 5 % [#permalink]

Show Tags

17 Jun 2016, 23:15

Read the question carefully and focus on fundamentals...5% Nacl by volume means means 5 percent of 10000 gallons which is 500 gallons of Nacl....so in a total of 10000 gallons.....500 gallons is Nacl.... now of 9500 gallons of water....2500 goes out because of evaporation...we have now 7000 gallons of water....further 7500 gallons of total solution....to calculate now how much percent is Nacl...simply perform 500*100/7500 leading to correct answer

A tank contains 10,000 gallons of a solution that is 5 % [#permalink]

Show Tags

18 Jun 2016, 01:06

nero44 wrote:

A tank contains 10,000 gallons of a solution that is 5 percent sodium chloride by volume. If 2,500 gallons of water evaporate from the tank, the remaining solution will be approximately what percent sodium chloride?

(A) 1.25% (B) 3.75% (C) 6.25% (D) 6.67% (E) 11.7%

Attachment:

Capture.PNG [ 3.51 KiB | Viewed 2401 times ]

Final concentration of NACL is \(\frac{500}{7500}\)*100 =>\(6.67\)% Answer will be (D) _________________

Thanks and Regards

Abhishek....

PLEASE FOLLOW THE RULES FOR POSTING IN QA AND VA FORUM AND USE SEARCH FUNCTION BEFORE POSTING NEW QUESTIONS

After days of waiting, sharing the tension with other applicants in forums, coming up with different theories about invites patterns, and, overall, refreshing my inbox every five minutes to...

I was totally freaking out. Apparently, most of the HBS invites were already sent and I didn’t get one. However, there are still some to come out on...

In early 2012, when I was working as a biomedical researcher at the National Institutes of Health , I decided that I wanted to get an MBA and make the...