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

It is currently 15 Oct 2019, 11:53

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

M14-22

  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: 58340
M14-22  [#permalink]

Show Tags

New post 16 Sep 2014, 00:53
1
2
00:00
A
B
C
D
E

Difficulty:

  5% (low)

Question Stats:

92% (01:11) correct 8% (01:11) wrong based on 59 sessions

HideShow timer Statistics

When two identical liquids are mixed, the temperature of the mix can be found by the formula

\(T = \frac{Q1*T1 + Q2*T2}{Q1 + Q2}\),

where \(Q1\) and \(Q2\) are quantities of liquids being mixed and \(T1\) and \(T2\) are temperatures of these liquids.

If the temperature of the mix of \(N\) liters of 10-degree water with \(2N\) liters of \(X\)-degree water is 20 degrees, what is \(X\)?


A. 21
B. 23
C. 25
D. 30
E. the data is not sufficient to answer the question

_________________
Math Expert
User avatar
V
Joined: 02 Sep 2009
Posts: 58340
Re M14-22  [#permalink]

Show Tags

New post 16 Sep 2014, 00:53
1
Official Solution:


When two identical liquids are mixed, the temperature of the mix can be found by the formula

\(T = \frac{Q1*T1 + Q2*T2}{Q1 + Q2}\),

where \(Q1\) and \(Q2\) are quantities of liquids being mixed and \(T1\) and \(T2\) are temperatures of these liquids.

If the temperature of the mix of \(N\) liters of 10-degree water with \(2N\) liters of \(X\)-degree water is 20 degrees, what is \(X\)?


A. 21
B. 23
C. 25
D. 30
E. the data is not sufficient to answer the question

\(T = \frac{N10 + 2NX}{N + 2N} = \frac{2X + 10}{3} = 20\). From this equation, \(X = 25\).

Answer: C
_________________
Intern
Intern
avatar
Joined: 27 Sep 2015
Posts: 18
WE: Sales (Transportation)
Re: M14-22  [#permalink]

Show Tags

New post 06 Feb 2016, 11:53
Why is it that you can cancel all the 'N' from the equation T=N10+2NX /N+2N
Math Expert
User avatar
V
Joined: 02 Sep 2009
Posts: 58340
Re: M14-22  [#permalink]

Show Tags

New post 06 Feb 2016, 11:58
SVP
SVP
User avatar
V
Joined: 26 Mar 2013
Posts: 2345
Reviews Badge CAT Tests
Re: M14-22  [#permalink]

Show Tags

New post 06 Feb 2016, 14:06
We can plug-in numbers

Q1=N=1 & Q2=2N=2

20= [(1*10)+ (2*T2)]/3

60= 10 +2T2..........> T2=25

Answer:C
Intern
Intern
avatar
B
Joined: 30 Sep 2017
Posts: 15
Re: M14-22  [#permalink]

Show Tags

New post 17 Dec 2018, 21:12
Where is it mentioned that both liquids are identical?

Bunuel
GMAT Club Bot
Re: M14-22   [#permalink] 17 Dec 2018, 21:12
Display posts from previous: Sort by

M14-22

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

Moderators: chetan2u, Bunuel






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