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

It is currently 15 Nov 2018, 04:39

ISB R1 results on Nov 15:

Join Chat Room for Live Updates


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
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.
  • GMATbuster's Weekly GMAT Quant Quiz # 9

     November 17, 2018

     November 17, 2018

     09:00 AM PST

     11:00 AM PST

    Join the Quiz Saturday November 17th, 9 AM PST. The Quiz will last approximately 2 hours. Make sure you are on time or you will be at a disadvantage.

M00-01

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

Hide Tags

Math Expert
User avatar
V
Joined: 02 Sep 2009
Posts: 50608
M00-01  [#permalink]

Show Tags

New post 15 Sep 2014, 23:14
2
11
00:00
A
B
C
D
E

Difficulty:

  95% (hard)

Question Stats:

49% (01:45) correct 51% (01:52) wrong based on 84 sessions

HideShow timer Statistics

At an upscale fast-food restaurant, Shin can buy 3 burgers, 7 shakes, and one cola for $120. At the same place it would cost $164.50 for 4 burgers, 10 shakes, and one cola. How much would it cost for a meal of one burger, one shake, and one cola?

A. $21
B. $27
C. $31
D. $41
E. It cannot be determined

_________________

New to the Math Forum?
Please read this: Ultimate GMAT Quantitative Megathread | All You Need for Quant | PLEASE READ AND FOLLOW: 12 Rules for Posting!!!

Resources:
GMAT Math Book | Triangles | Polygons | Coordinate Geometry | Factorials | Circles | Number Theory | Remainders; 8. Overlapping Sets | PDF of Math Book; 10. Remainders | GMAT Prep Software Analysis | SEVEN SAMURAI OF 2012 (BEST DISCUSSIONS) | Tricky questions from previous years.

Collection of Questions:
PS: 1. Tough and Tricky questions; 2. Hard questions; 3. Hard questions part 2; 4. Standard deviation; 5. Tough Problem Solving Questions With Solutions; 6. Probability and Combinations Questions With Solutions; 7 Tough and tricky exponents and roots questions; 8 12 Easy Pieces (or not?); 9 Bakers' Dozen; 10 Algebra set. ,11 Mixed Questions, 12 Fresh Meat

DS: 1. DS tough questions; 2. DS tough questions part 2; 3. DS tough questions part 3; 4. DS Standard deviation; 5. Inequalities; 6. 700+ GMAT Data Sufficiency Questions With Explanations; 7 Tough and tricky exponents and roots questions; 8 The Discreet Charm of the DS; 9 Devil's Dozen!!!; 10 Number Properties set., 11 New DS set.


What are GMAT Club Tests?
Extra-hard Quant Tests with Brilliant Analytics

Math Expert
User avatar
V
Joined: 02 Sep 2009
Posts: 50608
Re M00-01  [#permalink]

Show Tags

New post 15 Sep 2014, 23:14
2
2
Official Solution:

At an upscale fast-food restaurant, Shin can buy 3 burgers, 7 shakes, and one cola for $120. At the same place it would cost $164.50 for 4 burgers, 10 shakes, and one cola. How much would it cost for a meal of one burger, one shake, and one cola?

A. $21
B. $27
C. $31
D. $41
E. It cannot be determined


Let's suppose that the price of a burger is \(B\), of a shake - \(S\) and that of a cola is \(C\). We can then construct these equations:
\(3B+7S+C = 120\)
\(4B+10S+C = 164.5\)

Subtracting the first equation from the second gives us \(B+3S=44.5\).

Now if we subtract the new equation two times from first or 3 times from second we will get \(B+S+C=31\). In any case, there is no necessity to know each item's price, just the sum.


Answer: C
_________________

New to the Math Forum?
Please read this: Ultimate GMAT Quantitative Megathread | All You Need for Quant | PLEASE READ AND FOLLOW: 12 Rules for Posting!!!

Resources:
GMAT Math Book | Triangles | Polygons | Coordinate Geometry | Factorials | Circles | Number Theory | Remainders; 8. Overlapping Sets | PDF of Math Book; 10. Remainders | GMAT Prep Software Analysis | SEVEN SAMURAI OF 2012 (BEST DISCUSSIONS) | Tricky questions from previous years.

Collection of Questions:
PS: 1. Tough and Tricky questions; 2. Hard questions; 3. Hard questions part 2; 4. Standard deviation; 5. Tough Problem Solving Questions With Solutions; 6. Probability and Combinations Questions With Solutions; 7 Tough and tricky exponents and roots questions; 8 12 Easy Pieces (or not?); 9 Bakers' Dozen; 10 Algebra set. ,11 Mixed Questions, 12 Fresh Meat

DS: 1. DS tough questions; 2. DS tough questions part 2; 3. DS tough questions part 3; 4. DS Standard deviation; 5. Inequalities; 6. 700+ GMAT Data Sufficiency Questions With Explanations; 7 Tough and tricky exponents and roots questions; 8 The Discreet Charm of the DS; 9 Devil's Dozen!!!; 10 Number Properties set., 11 New DS set.


What are GMAT Club Tests?
Extra-hard Quant Tests with Brilliant Analytics

Intern
Intern
avatar
B
Joined: 09 Feb 2015
Posts: 20
GMAT ToolKit User
Re: M00-01  [#permalink]

Show Tags

New post 18 May 2015, 05:50
4
4
Another solution:
Given: 3B+ 7S + C = 120 Multiply by 3: 9B+21S+3C=360 (1)
4B + 10S + C = 164.5 Multiply by 2: 8B + 20S + 2C = 329 (2)
=> (1) - (2) = 31.
Manager
Manager
User avatar
Joined: 02 Nov 2014
Posts: 194
GMAT Date: 08-04-2015
GMAT ToolKit User Reviews Badge
Re M00-01  [#permalink]

Show Tags

New post 13 Oct 2015, 03:50
I think this is a high-quality question and I agree with explanation. Great Q.
Thanks,

Binit.
Board of Directors
User avatar
P
Joined: 17 Jul 2014
Posts: 2645
Location: United States (IL)
Concentration: Finance, Economics
GMAT 1: 650 Q49 V30
GPA: 3.92
WE: General Management (Transportation)
GMAT ToolKit User Premium Member Reviews Badge
Re: M00-01  [#permalink]

Show Tags

New post 14 Oct 2015, 11:27
Multiply first equation by 2:
6B+14S+2C=240

subtract second equation from the new one
6B+14S+2C=240 _
4B+10S+1C=164.50

get:
2B+4S+1C=75.50

now, if we subtract from the second equation the first one before we multiply, we get:
4B+10S+1C=164.50 _
3B+7S+1C=120
and get B+3S = 44.50

ok, now we're getting to something.
2B+4S+1C=75.50
and
B+3S = 44.50
substract the second one from the first one and get B+S+C=31.
answer choice C.
Intern
Intern
User avatar
B
Joined: 14 May 2016
Posts: 15
Schools: INSEAD Jan '20
Premium Member
Re: M00-01  [#permalink]

Show Tags

New post 28 Aug 2016, 11:46
1
I understood it when I solved it again without any time constraints...
Here's what I learned from this:

When writing more than one linear equation (with the same variables), write them one under the other for the facilitation of a quick insight!
Intern
Intern
avatar
Joined: 13 Jul 2016
Posts: 1
GMAT 1: 740 Q49 V41
Reviews Badge
Re: M00-01  [#permalink]

Show Tags

New post 27 Dec 2016, 00:16
Is there any way for solving 3 variable equations as fast as possible.
Intern
Intern
avatar
B
Joined: 17 Dec 2016
Posts: 13
Location: United States (NY)
Concentration: Sustainability
GPA: 3.76
WE: Other (Military & Defense)
GMAT ToolKit User
Re M00-01  [#permalink]

Show Tags

New post 25 Jul 2017, 19:12
I think this is a high-quality question and I agree with explanation. I was looking for some type of hook. Very good question!
Manager
Manager
avatar
B
Joined: 14 Jun 2016
Posts: 67
Location: India
GMAT 1: 610 Q49 V21
WE: Engineering (Manufacturing)
Reviews Badge
Re: M00-01  [#permalink]

Show Tags

New post 22 Aug 2017, 10:04
Very difficult to answer under time constraints; any simple way to figure out or hit and trial is the only option?
_________________

If you appreciate my post then please click +1Kudos :)

Math Expert
User avatar
V
Joined: 02 Sep 2009
Posts: 50608
Re: M00-01  [#permalink]

Show Tags

New post 22 Aug 2017, 10:21
Intern
Intern
avatar
B
Joined: 27 Sep 2016
Posts: 1
Location: India
Concentration: Strategy, General Management
WE: Information Technology (Computer Software)
CAT Tests
Re: M00-01  [#permalink]

Show Tags

New post 02 Dec 2017, 01:06
I did it like this-

3B + 7S+ Z= 120 -------1

4B + 10S +Z = 164.50 -----------2

Multiply eq-1 by 3 & eq-2 by 2

9B + 21S+ 3Z= 360

8B + 20S+ 2Z = 329

Now subtract above eqns
B + S+ Z= 31

##############################
Intern
Intern
avatar
S
Joined: 20 Sep 2012
Posts: 7
Location: Russian Federation
Concentration: Finance, General Management
GMAT 1: 710 Q49 V38
GPA: 3.5
GMAT ToolKit User Premium Member Reviews Badge CAT Tests
Re M00-01  [#permalink]

Show Tags

New post 28 Dec 2017, 06:07
I think this is a high-quality question and I agree with explanation.
Intern
Intern
avatar
Joined: 10 Sep 2017
Posts: 1
Re M00-01  [#permalink]

Show Tags

New post 15 Jan 2018, 17:54
I think this is a high-quality question and I don't agree with the explanation. I have now understood the equations underlying.. Perhaps, it should have been explained. Nevertheless, a quality question !
Intern
Intern
avatar
B
Joined: 22 Jul 2018
Posts: 6
CAT Tests
Re: M00-01  [#permalink]

Show Tags

New post 03 Sep 2018, 10:19
buan15 wrote:
Very difficult to answer under time constraints; any simple way to figure out or hit and trial is the only option?


There's a mechanical way of solving any question like this without relying on hit and trial based on linear algebra

The idea is that we are manipulating the equations by multiplying with a constant, and then adding the 2 equations to get our desired equation.
Our desired equation is one that has the same coefficient for B, S and C

eq 1 - 3B + 7S + C multiply this equation by x
eq 2 - 4B + 10S + C multiply this equation by y

Since we want the coefficients the same after adding, 7x+ 4y (coefficient of B) = 7x + 10y (coefficient of S) = x+y (coefficient of C)
this gives x = -3y/2
Since for simplicity we want x & y to be integers, we can use y = -2, so x = 3
So if we multiply eq 1 by 3 and eq 2 by -2, and add the two equations together we will get B + S + C.

Not sure if my explanation is complicated but in my opinion its a very easy and foolproof way to solve these type of questions.
GMAT Club Bot
Re: M00-01 &nbs [#permalink] 03 Sep 2018, 10:19
Display posts from previous: Sort by

M00-01

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

Moderators: chetan2u, Bunuel



Copyright

GMAT Club MBA Forum Home| About| Terms and Conditions and Privacy Policy| GMAT Club Rules| Contact| Sitemap

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

Kindly note that the GMAT® test is a registered trademark of the Graduate Management Admission Council®, and this site has neither been reviewed nor endorsed by GMAC®.