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

 It is currently 14 Nov 2018, 09:46

Join Chat Room for Live Updates

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

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

Events & Promotions

Events & Promotions in November
PrevNext
SuMoTuWeThFrSa
28293031123
45678910
11121314151617
18192021222324
2526272829301
Open Detailed Calendar
• Free GMAT Strategy Webinar

November 17, 2018

November 17, 2018

07:00 AM PST

09:00 AM PST

Nov. 17, 7 AM PST. Aiming to score 760+? Attend this FREE session to learn how to Define your GMAT Strategy, Create your Study Plan and Master the Core Skills to excel on the GMAT.

At a certain industrial manufacturer, an open tank contains 6% fluorin

Author Message
TAGS:

Hide Tags

Intern
Joined: 18 Jul 2017
Posts: 45
At a certain industrial manufacturer, an open tank contains 6% fluorin  [#permalink]

Show Tags

30 Jun 2018, 05:50
5
00:00

Difficulty:

45% (medium)

Question Stats:

67% (01:56) correct 33% (02:11) wrong based on 115 sessions

HideShow timer Statistics

At a certain industrial manufacturer, an open tank contains 6% fluorine dissolved in water. If the tank holds 1000 gallons, and 10 gallons of the total volume evaporate as water each day, what is the concentration of fluorine after 25 days

A. 4%
B. 6%
C. 8%
D. 10%
E. 15%
Manager
Status: Student
Joined: 06 Jun 2018
Posts: 61
Location: India
Concentration: Finance, Marketing
GPA: 4
Re: At a certain industrial manufacturer, an open tank contains 6% fluorin  [#permalink]

Show Tags

30 Jun 2018, 08:15
Quantity of fluorine - 6% of 1000= 60 gallons

10 gallons of water evaporate everyday
So in 25 days - 250 gallons of water evaporates
remaining quantity -1000-250=750
concentration of fluorine after 25 days - (60/750 )*100=8% Ans C

Posted from my mobile device
Intern
Joined: 26 Mar 2015
Posts: 10
Re: At a certain industrial manufacturer, an open tank contains 6% fluorin  [#permalink]

Show Tags

30 Jun 2018, 22:46
Given 1000 gallons of sol.
6% flourine = 60
Rest water = 940
Now 10 gallons per day of total sol evaporates as water tricky
10 gallons per day so in 25 days 25x10 =250 gallons evaporated
Solution left 1000-250=750
So flourine concern = 60/750 = 0.08 =8%
Intern
Joined: 28 Jun 2018
Posts: 46
Re: At a certain industrial manufacturer, an open tank contains 6% fluorin  [#permalink]

Show Tags

25 Jul 2018, 03:02
Hey guys, a little confused...why are we doing the last step? Didn't some of the 60 gallons of the fluorine evaporate as well? How do we get that? :/Antreev
Manager
Status: Student
Joined: 06 Jun 2018
Posts: 61
Location: India
Concentration: Finance, Marketing
GPA: 4
Re: At a certain industrial manufacturer, an open tank contains 6% fluorin  [#permalink]

Show Tags

25 Jul 2018, 03:23
hibobotamuss wrote:
Hey guys, a little confused...why are we doing the last step? Didn't some of the 60 gallons of the fluorine evaporate as well? How do we get that? :/Antreev

The question clearly mentions that water evaporates and not fluorine.

Posted from my mobile device
Board of Directors
Status: QA & VA Forum Moderator
Joined: 11 Jun 2011
Posts: 4207
Location: India
GPA: 3.5
Re: At a certain industrial manufacturer, an open tank contains 6% fluorin  [#permalink]

Show Tags

25 Jul 2018, 05:59
wishalsp333 wrote:
At a certain industrial manufacturer, an open tank contains 6% fluorine dissolved in water. If the tank holds 1000 gallons, and 10 gallons of the total volume evaporate as water each day, what is the concentration of fluorine after 25 days

A. 4%
B. 6%
C. 8%
D. 10%
E. 15%

Total Volume = 1000 Gallons ; Fluorine = 60 Gallons & Water = 940 Gallons

Each day 10 gallons evaporates, so in 25 days 250 Gallons of water evaporates and we are left with 690 gallons of water and 60 Gallons of Fluorine.

Thus after 25 days total Volume is 750 Gallons out of which Fluorine is 60 Gallons.

So, Concentration of fluorine after 25 days is $$\frac{60}{750}*100$$ = 8% , Answer must be (C)
_________________

Thanks and Regards

Abhishek....

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

How to use Search Function in GMAT Club | Rules for Posting in QA forum | Writing Mathematical Formulas |Rules for Posting in VA forum | Request Expert's Reply ( VA Forum Only )

Target Test Prep Representative
Affiliations: Target Test Prep
Joined: 04 Mar 2011
Posts: 2830
Re: At a certain industrial manufacturer, an open tank contains 6% fluorin  [#permalink]

Show Tags

26 Jul 2018, 15:27
wishalsp333 wrote:
At a certain industrial manufacturer, an open tank contains 6% fluorine dissolved in water. If the tank holds 1000 gallons, and 10 gallons of the total volume evaporate as water each day, what is the concentration of fluorine after 25 days

A. 4%
B. 6%
C. 8%
D. 10%
E. 15%

At the beginning, there are 0.06 x 1000 = 60 gallons of fluorine. After 25 days there are 1000 - 10 x 25 = 1000 - 250 = 750 gallons of liquid left. Therefore, the concentration of fluorine after 25 days is:

60/750 = 6/75 = 2/25 = 8/100 = 8%

_________________

Jeffery Miller

GMAT Quant Self-Study Course
500+ lessons 3000+ practice problems 800+ HD solutions

Re: At a certain industrial manufacturer, an open tank contains 6% fluorin &nbs [#permalink] 26 Jul 2018, 15:27
Display posts from previous: Sort by