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

It is currently 21 Oct 2019, 00:45

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

A bookstore that sells used books sells each of its paperbac

  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: 58415
A bookstore that sells used books sells each of its paperbac  [#permalink]

Show Tags

New post 23 Feb 2014, 07:48
1
11
00:00
A
B
C
D
E

Difficulty:

  15% (low)

Question Stats:

73% (01:12) correct 27% (01:15) wrong based on 558 sessions

HideShow timer Statistics

The Official Guide For GMAT® Quantitative Review, 2ND Edition

A bookstore that sells used books sells each of its paperback books for a certain price and each of its hardcover books for a certain price. If Joe, Maria, and Paul bought books in this store, how much did Maria pay for 1 paperback book and 1 hardcover book?

(1) Joe bought 2 paperback books and 3 hardcover books for $12.50.
(2) Paul bought 4 paperback books and 6 hardcover books for $25.00.

Data Sufficiency
Question: 108
Category: Algebra Applied problems
Page: 161
Difficulty: 650


GMAT Club is introducing a new project: The Official Guide For GMAT® Quantitative Review, 2ND Edition - Quantitative Questions Project

Each week we'll be posting several questions from The Official Guide For GMAT® Quantitative Review, 2ND Edition and then after couple of days we'll provide Official Answer (OA) to them along with a slution.

We'll be glad if you participate in development of this project:
1. Please provide your solutions to the questions;
2. Please vote for the best solutions by pressing Kudos button;
3. Please vote for the questions themselves by pressing Kudos button;
4. Please share your views on difficulty level of the questions, so that we have most precise evaluation.

Thank you!

_________________
Most Helpful Expert Reply
Math Expert
User avatar
V
Joined: 02 Sep 2009
Posts: 58415
Re: A bookstore that sells used books sells each of its paperbac  [#permalink]

Show Tags

New post 23 Feb 2014, 07:48
5
SOLUTION

A bookstore that sells used books sells each of its paperback books for a certain price and each of its hardcover books for a certain price. If Joe, Maria, and Paul bought books in this store, how much did Maria pay for 1 paperback book and 1 hardcover book?

We should find the value of p+h, where p is the price of one paperback and h is the price of one hard cover book.

(1) Joe bought 2 paperback books and 3 hardcover books for $12.50 --> 2p + 3h = 12.5. Not sufficient.

(2) Paul bought 4 paperback books and 6 hardcover books for $25.00 --> 4p + 6h = 25. Not sufficient.

(1)+(2) We can get 4p + 6h = 25 by multiplying 2p + 3h = 12.5 by 2, thus even when combining the statements we still have only one equation. Not sufficient.

Answer: E.
_________________
General Discussion
Director
Director
User avatar
Joined: 25 Apr 2012
Posts: 660
Location: India
GPA: 3.21
WE: Business Development (Other)
Reviews Badge
Re: A bookstore that sells used books sells each of its paperbac  [#permalink]

Show Tags

New post 24 Feb 2014, 00:27
2
1
A bookstore that sells used books sells each of its paperback books for a certain price and each of its hardcover books for a certain price. If Joe, Maria, and Paul bought books in this store, how much did Maria pay for 1 paperback book and 1 hardcover book?

(1) Joe bought 2 paperback books and 3 hardcover books for $12.50.
(2) Paul bought 4 paperback books and 6 hardcover books for $25.00.



Sol: Let the price of paperbook be "X" and that of Hardcover be "Y". So we need to find X+Y?

St 1: 2X+3Y=12.5. There are multiple values possible so not sufficient.
A and D ruled out

St 2: 4X+6Y=25 or 2X+3Y=12.5 which is same information as St 1 So B ruled out

Combining the 2 statements, we get no new information so ans is E.

650 level is okay
_________________

“If you can't fly then run, if you can't run then walk, if you can't walk then crawl, but whatever you do you have to keep moving forward.”
Manager
Manager
avatar
Joined: 20 Dec 2013
Posts: 224
Location: India
Re: A bookstore that sells used books sells each of its paperbac  [#permalink]

Show Tags

New post 24 Feb 2014, 03:48
Option E.
From S1:Let price per paperback=x &
price per hardcover=y
2x+3y=12.50.Not suff since two variables,one equation can't be solved.

From S2:4x+6y=25
Nothing but 2(2x+3y)=25
OR repetition of eqn from S1.Not suff.

Combining we can't sove since both are basically the same equations.
Intern
Intern
User avatar
Status: Never Give up!!!
Joined: 03 Aug 2012
Posts: 46
Location: India
Concentration: Finance, General Management
GMAT ToolKit User
Re: A bookstore that sells used books sells each of its paperbac  [#permalink]

Show Tags

New post 24 Feb 2014, 04:22
1
Let the price of paperbacks be 'x'
the price of hard cover book be 'y'

From Statement 1:- Joe bought 2 paperback books and 3 hardcover books for $12.50.
Thus 2x+3y = 12.50
This is one equation with 2 unknowns hence it cannot be solved. So statement 1 alone is insufficient

From Statement 2:- Paul bought 4 paperback books and 6 hardcover books for $25.00
Thus 4x+6y = 25
Again it is one equation with 2 unknowns. So statement 2 alone is insufficient.

Combining both the statements we get 2 equations:-
1. 2x+3y = 12.5
2. 4x+6y = 25

Now linear equations with 2 unknowns can only be solved it both the equations are different i.e not the same or multiplies of each other.
Here equation 2 is a multiple of equation 1. Equation 2 = (Equation 1)x2

Thus this pair of equations cannot be solved. and hence even after combining both the equations the solution is not possible.

Hence Option (E) is the answer
Manager
Manager
avatar
Status: suffer now and live forever as a champion!!!
Joined: 01 Sep 2013
Posts: 101
Location: India
Dheeraj: Madaraboina
GPA: 3.5
WE: Information Technology (Computer Software)
Re: A bookstore that sells used books sells each of its paperbac  [#permalink]

Show Tags

New post 03 Jun 2014, 22:06
Bunuel wrote:
SOLUTION

A bookstore that sells used books sells each of its paperback books for a certain price and each of its hardcover books for a certain price. If Joe, Maria, and Paul bought books in this store, how much did Maria pay for 1 paperback book and 1 hardcover book?

We should find the value of p+h, where p is the price of one paperback and h is the price of one hard cover book.

(1) Joe bought 2 paperback books and 3 hardcover books for $12.50 --> 2p + 3h = 12.5. Not sufficient.

(2) Paul bought 4 paperback books and 6 hardcover books for $25.00 --> 4p + 6h = 25. Not sufficient.

(1)+(2) We can get 4p + 6h = 25 by multiplying 2p + 3h = 12.5 by 2, thus even when combining the statements we still have only one equation. Not sufficient.

Answer: E.




Hi Bunuel ,

Can't we get Answer as' D' by using trial and error method.

2 PB + 3 HC = 12.50$
The equation satisfies for PB =4 AND HC = 1.5 ;This is the only pair that satisifies the above equation ;
Therefore, can't we say that for one PB +one HC = 2+ 1.5 = 3.5 $

Please explain whether my approach is correct (or ) wrong.

Help is appreciated. :)
Math Expert
User avatar
V
Joined: 02 Sep 2009
Posts: 58415
Re: A bookstore that sells used books sells each of its paperbac  [#permalink]

Show Tags

New post 04 Jun 2014, 03:38
dheeraj24 wrote:
Bunuel wrote:
SOLUTION

A bookstore that sells used books sells each of its paperback books for a certain price and each of its hardcover books for a certain price. If Joe, Maria, and Paul bought books in this store, how much did Maria pay for 1 paperback book and 1 hardcover book?

We should find the value of p+h, where p is the price of one paperback and h is the price of one hard cover book.

(1) Joe bought 2 paperback books and 3 hardcover books for $12.50 --> 2p + 3h = 12.5. Not sufficient.

(2) Paul bought 4 paperback books and 6 hardcover books for $25.00 --> 4p + 6h = 25. Not sufficient.

(1)+(2) We can get 4p + 6h = 25 by multiplying 2p + 3h = 12.5 by 2, thus even when combining the statements we still have only one equation. Not sufficient.

Answer: E.




Hi Bunuel ,

Can't we get Answer as' D' by using trial and error method.

2 PB + 3 HC = 12.50$
The equation satisfies for PB =4 AND HC = 1.5 ;This is the only pair that satisifies the above equation ;
Therefore, can't we say that for one PB +one HC = 2+ 1.5 = 3.5 $

Please explain whether my approach is correct (or ) wrong.

Help is appreciated. :)


How did you get that p=4 and h=1.5 is the only solution of 2p + 3h = 12.5 ? What about p=4.75 and h=1, p=3.25 and h=2, ... ?
_________________
Director
Director
User avatar
P
Status: Professional GMAT Tutor
Affiliations: AB, cum laude, Harvard University (Class of '02)
Joined: 10 Jul 2015
Posts: 706
Location: United States (CA)
Age: 39
GMAT 1: 770 Q47 V48
GMAT 2: 730 Q44 V47
GMAT 3: 750 Q50 V42
GRE 1: Q168 V169
WE: Education (Education)
A bookstore that sells used books sells each of its paperbac  [#permalink]

Show Tags

New post 28 Mar 2016, 18:17
Here is a visual that should help.

Observations:

1) Since the cost of all the goods is the same for everyone, it is irrelevant who bought what, so don't bother complicating the question by including this information.

2) Usually, when we have two equations with two variables, this is sufficient...unless the 2nd equation happens to be the same as the first, which is what happened here.
Attachments

Screen Shot 2016-03-28 at 6.17.35 PM.png
Screen Shot 2016-03-28 at 6.17.35 PM.png [ 110.42 KiB | Viewed 11771 times ]


_________________
Harvard grad and 99% GMAT scorer, offering expert, private GMAT tutoring and coaching worldwide since 2002.

One of the only known humans to have taken the GMAT 5 times and scored in the 700s every time (700, 710, 730, 750, 770), including verified section scores of Q50 / V47, as well as personal bests of 8/8 IR (2 times), 6/6 AWA (4 times), 50/51Q and 48/51V.

You can download my official test-taker score report (all scores within the last 5 years) directly from the Pearson Vue website: https://tinyurl.com/y7knw7bt Date of Birth: 09 December 1979.

GMAT Action Plan and Free E-Book - McElroy Tutoring

Contact: mcelroy@post.harvard.edu (I do not respond to PMs on GMAT Club) or find me on reddit: http://www.reddit.com/r/GMATpreparation
Director
Director
avatar
G
Joined: 09 Mar 2018
Posts: 994
Location: India
Re: A bookstore that sells used books sells each of its paperbac  [#permalink]

Show Tags

New post 15 Feb 2019, 06:58
Bunuel wrote:
The Official Guide For GMAT® Quantitative Review, 2ND Edition

A bookstore that sells used books sells each of its paperback books for a certain price and each of its hardcover books for a certain price. If Joe, Maria, and Paul bought books in this store, how much did Maria pay for 1 paperback book and 1 hardcover book?

(1) Joe bought 2 paperback books and 3 hardcover books for $12.50.
(2) Paul bought 4 paperback books and 6 hardcover books for $25.00.



What i have noticed in such question types is that, we dont have any relationship between these 3 people, if we had some relationship, we could have actually commented on the cost of 1 paperback book and 1 hardcover book for Maria, Since nothing is there and both the statements give the same relationship

answer is E

from 1) 2 x + 3 y = 12.50
from 2) 2x + 3y = 12.50
_________________
If you notice any discrepancy in my reasoning, please let me know. Lets improve together.

Quote which i can relate to.
Many of life's failures happen with people who do not realize how close they were to success when they gave up.
GMAT Club Bot
Re: A bookstore that sells used books sells each of its paperbac   [#permalink] 15 Feb 2019, 06:58
Display posts from previous: Sort by

A bookstore that sells used books sells each of its paperbac

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





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