January 17, 2019 January 17, 2019 08:00 AM PST 09:00 AM PST Learn the winning strategy for a high GRE score — what do people who reach a high score do differently? We're going to share insights, tips and strategies from data we've collected from over 50,000 students who used examPAL. January 19, 2019 January 19, 2019 07:00 AM PST 09:00 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.
Author 
Message 
TAGS:

Hide Tags

Math Expert
Joined: 02 Sep 2009
Posts: 52254

In a certain classroom, there are 80 books, of which 24 are
[#permalink]
Show Tags
16 Jul 2012, 03:54
Question Stats:
80% (01:53) correct 20% (02:07) wrong based on 986 sessions
HideShow timer Statistics




Math Expert
Joined: 02 Sep 2009
Posts: 52254

In a certain classroom, there are 80 books, of which 24 are
[#permalink]
Show Tags
16 Jul 2012, 12:07




Manager
Joined: 28 Feb 2012
Posts: 109
Concentration: Strategy, International Business
GPA: 3.9
WE: Marketing (Other)

Re: In a certain classroom, there are 80 books, of which 24 are
[#permalink]
Show Tags
17 Jul 2012, 21:26
From the first statement: x+(x+6)=24, so x=9 (fiction books written in Spanish). from st. 2: x+(x+5)=23, x=9 (fiction books written in Spanish) Both statements separetely suff., so answer D. I wonder why they provide total number of books (80 books), maybe i am missing something?
_________________
If you found my post useful and/or interesting  you are welcome to give kudos!



Intern
Joined: 02 Apr 2012
Posts: 2

Re: In a certain classroom, there are 80 books, of which 24 are
[#permalink]
Show Tags
17 Jul 2012, 21:50
Answer is D , as we can use both the statements to arrive at a unique solution
statement 1: (1) Of the fiction books, there are 6 more that are not written in Spanish than are written in Spanish.
total fiction books = 24, so ( x+ x+6 = 24) where x is the fiction books in spanish
statement 2 states that (2) Of the books written in Spanish, there are 5 more nonfiction books than fiction books.
so x + x+ 5 = 23 , where x is the fiction books in spanish
as we can arrive at a unique solution from both statements alone ... answer is d



Manager
Joined: 08 Apr 2013
Posts: 151

Re: In a certain classroom, there are 80 books, of which 24 are
[#permalink]
Show Tags
03 Dec 2013, 21:13
IT IS still ven diagram call x= number of book fiction in spanish we have 24x, x and 23x from 1 (24x) x=6 we can get x from 2 (23x) x =5 we can get x oa is d
_________________
If anyone in this gmat forum is in England,Britain, pls, email to me, (thanghnvn@gmail.com) . I have some questions and need your advise. Thank a lot.



Intern
Joined: 25 Aug 2014
Posts: 7

Re: In a certain classroom, there are 80 books, of which 24 are
[#permalink]
Show Tags
22 Mar 2016, 14:59
Can some one explain this problem with proper Venn diagram ?



CEO
Joined: 20 Mar 2014
Posts: 2639
Concentration: Finance, Strategy
GPA: 3.7
WE: Engineering (Aerospace and Defense)

In a certain classroom, there are 80 books, of which 24 are
[#permalink]
Show Tags
22 Mar 2016, 15:51
shekharshrek wrote: Can some one explain this problem with proper Venn diagram ? The 2X2 matrix is a variation of the venn diagram method and will help you solve the questions correctly and in lesser time than venn diagrams. But for the sake of your question, refer to the attached image for description of the variables. Attachment:
20160322_194442.jpg [ 18.34 KiB  Viewed 5769 times ]
Spanish = b+c = 23 Fiction = a+b = 24 Per the question, total books = 80=a+b+c+d (d = not fiction and not Spanish) The question asks us the value of b = ? Per statement 1, a = 6+b > clearly sufficient, b=9 Per statement 2, c = 5+b > clearly sufficient, b=9 Both statements are sufficient. D is the correct answer. Hope this helps. Learn good strategies to answer questions and not just solving questions blindly.



Intern
Joined: 25 Aug 2014
Posts: 7

Re: In a certain classroom, there are 80 books, of which 24 are
[#permalink]
Show Tags
23 Mar 2016, 10:43
Engr2012Thanks , can you please focus more on the exact meaning of these 2 statements which are highlighted in accordance with the equation above. 1) Of the fiction books, there are 6 more that are not written in Spanish than are written in Spanish. (2) Of the books written in Spanish, there are 5 more nonfiction books than fiction books.



CEO
Joined: 20 Mar 2014
Posts: 2639
Concentration: Finance, Strategy
GPA: 3.7
WE: Engineering (Aerospace and Defense)

Re: In a certain classroom, there are 80 books, of which 24 are
[#permalink]
Show Tags
23 Mar 2016, 10:59
shekharshrek wrote: Engr2012Thanks , can you please focus more on the exact meaning of these 2 statements which are highlighted in accordance with the equation above. 1) Of the fiction books, there are 6 more that are not written in Spanish than are written in Spanish. (2) Of the books written in Spanish, there are 5 more nonfiction books than fiction books. Sure, if you look at the venn diagram, statement 1 mentions that "there are 6 more that are not written in Spanish than are written in Spanish" > Total fiction books = a+b, fiction + Spanish books = b , fiction and NOT Spanish = a Thus, per the statement, fiction + NOT Spanish = 6 + (fiction+Spanish) > a = 6+b Similarly, per statement 2, total Spanish books = b+c > Spanish ONLY = c and Spanish + fiction = b > c=b+5 Hope this helps.



Intern
Joined: 17 Jun 2017
Posts: 1
WE: Consulting (Computer Software)

Re: In a certain classroom, there are 80 books, of which 24 are
[#permalink]
Show Tags
31 Mar 2018, 14:03
brunel  I solved this using the table method as well. However, drawing out tables 3x is quite time consuming and I cannot seem to do it in under 3 minutes. Does 3 minutes seem reasonable to you or should I be solving this quicker? Thanks!



VP
Joined: 09 Mar 2016
Posts: 1287

In a certain classroom, there are 80 books, of which 24 are
[#permalink]
Show Tags
20 Apr 2018, 10:09
Bunuel wrote: SOLUTIONIn a certain classroom, there are 80 books, of which 24 are fiction and 23 are written in Spanish. How many of the fiction books are written in Spanish?Given: (1) Of the fiction books, there are 6 more that are not written in Spanish than are written in Spanish. So, \(x+x+6=24\) > \(x=9\). Sufficient. (2) Of the books written in Spanish, there are 5 more nonfiction books than fiction books. So, \(x+x+5=23\) > \(x=9\). Sufficient. Answer: D. (Total # of books is redundant information). Hope it's clear. Bunuel why didnt you use the formulas ? I mean group 1 +group +2  both +neither Total = 80 Group 1 is fiction book = 24 Group 2 is spanish book = 23 Both Spanish Fiction = X Neither = 33 80 = 24 +23  X + 33 why this formula doesnt work ? pushpitkc any idea? i itemized every number memtioned in the question ? what is first right step to tackle overlapping sets ?



Senior PS Moderator
Joined: 26 Feb 2016
Posts: 3334
Location: India
GPA: 3.12

In a certain classroom, there are 80 books, of which 24 are
[#permalink]
Show Tags
20 Apr 2018, 12:05
dave13 wrote: Bunuel wrote: SOLUTIONIn a certain classroom, there are 80 books, of which 24 are fiction and 23 are written in Spanish. How many of the fiction books are written in Spanish?Given: (1) Of the fiction books, there are 6 more that are not written in Spanish than are written in Spanish. So, \(x+x+6=24\) > \(x=9\). Sufficient. (2) Of the books written in Spanish, there are 5 more nonfiction books than fiction books. So, \(x+x+5=23\) > \(x=9\). Sufficient. Answer: D. (Total # of books is redundant information). Hope it's clear. Bunuel why didnt you use the formulas ? I mean group 1 +group +2  both +neither Total = 80 Group 1 is fiction book = 24 Group 2 is spanish book = 23 Both Spanish Fiction = X Neither = 33 80 = 24 +23  X + 33 why this formula doesnt work ? pushpitkc any idea? i itemized every number memtioned in the question ? what is first right step to tackle overlapping sets ? Hey dave13I think when you are told that of the 80 books, 24 are from the genre  Fiction and 23 of the books are written in Spanish, there could be some books which are both from the genre fiction and written in Spanish. You are calling that x. Till here, you are correct! But how do you come to a conclusion that those books which are neither fiction nor written in Spanish are 33? If 23 books are both from the genre fiction and written in Spanish, then there will be one book which is of the genre Fiction and not written in Spanish. The remaining books  56(80  23  1) in number fall in neither written in Spanish nor of the genre fiction. However, if each of the books written in Spanish is not from the genre Fiction, there would be 33(80  23  24) books which are neither written in Spanish nor of the genre fiction So, basically, the number of books which are neither written in Spanish nor of the genre fiction can be between 33 and 56. Hope this explanation clears your confusion why your method is incorrect.
_________________
You've got what it takes, but it will take everything you've got



VP
Joined: 09 Mar 2016
Posts: 1287

In a certain classroom, there are 80 books, of which 24 are
[#permalink]
Show Tags
21 Apr 2018, 13:58
pushpitkc wrote: dave13 wrote: Bunuel wrote: SOLUTIONIn a certain classroom, there are 80 books, of which 24 are fiction and 23 are written in Spanish. How many of the fiction books are written in Spanish?Given: (1) Of the fiction books, there are 6 more that are not written in Spanish than are written in Spanish. So, \(x+x+6=24\) > \(x=9\). Sufficient. (2) Of the books written in Spanish, there are 5 more nonfiction books than fiction books. So, \(x+x+5=23\) > \(x=9\). Sufficient. Answer: D. (Total # of books is redundant information). Hope it's clear. Bunuel why didnt you use the formulas ? I mean group 1 +group +2  both +neither Total = 80 Group 1 is fiction book = 24 Group 2 is spanish book = 23 Both Spanish Fiction = X Neither = 33 80 = 24 +23  X + 33 why this formula doesnt work ? pushpitkc any idea? i itemized every number memtioned in the question ? what is first right step to tackle overlapping sets ? Hey dave13I think when you are told that of the 80 books, 24 are from the genre  Fiction and 23 of the books are written in Spanish, there could be some books which are both from the genre fiction and written in Spanish. You are calling that x. Till here, you are correct! But how do you come to a conclusion that those books which are neither fiction nor written in Spanish are 33? If 23 books are both from the genre fiction and written in Spanish, then there will be one book which is of the genre Fiction and not written in Spanish. The remaining books  56(80  23  1) in number fall in neither written in Spanish nor of the genre fiction. However, if each of the books written in Spanish is not from the genre Fiction, there would be 33(80  23  24) books which are neither written in Spanish nor of the genre fiction So, basically, the number of books which are neither written in Spanish nor of the genre fiction can be between 33 and 56. Hope this explanation clears your confusion why your method is incorrect. Hi pushpitkc thanks for your explanation, ok now i understand that neither written in Spanish nor of the genre fiction can be between 33 and 56  that means we need to denote Neither as unknown X so i get Total = 80 Group 1 is fiction book = 24 Group 2 is spanish book = 23 Both Spanish Fiction = X Neither = X \(80 = 24 +23  X + X\) again doing something wrong ... but what ? i think i got it... so question is How many of the fiction books are written in Spanish? (1) Of the fiction books, there are 6 more that are not written in Spanish than are written in Spanish. let \(x\) be fiction book written in Spanish, then non Spanish fiction books are \(x+6\) neither = y : ? 80= x+x+6.... how to write \(group 1+group 2 both + neither\) ...still dont get



Senior PS Moderator
Joined: 26 Feb 2016
Posts: 3334
Location: India
GPA: 3.12

Re: In a certain classroom, there are 80 books, of which 24 are
[#permalink]
Show Tags
21 Apr 2018, 22:40
Hi dave13You will have to have different variables to represent "Neither" and "Both Fiction and Spanish". The equation will be written as 80 = 23 + 24 + X + Y(which cannot be solved as such) When you try and solve the first statement, where we are told "Of the fiction books, there are 6 more that is not written in Spanish than are written in Spanish"  if we assume the number of fiction books that are written in Spanish to be another variable, say "s", the fiction books not written in Spanish are "s + 6" Now, we know that the total number of fiction books is 24. We can now form the equation s+s+6 = 24 and solving the equation, we get s=9(which is the number of fiction books, written in Spanish) We can now calculate the number of fiction books that are written in Spanish using statement 1 alone. Hence, the answer has to be A or D. Similarly, we solve for statement 2 and because the information given in statement 2 is also enough by itself, we arrive at the solution D!
_________________
You've got what it takes, but it will take everything you've got




Re: In a certain classroom, there are 80 books, of which 24 are &nbs
[#permalink]
21 Apr 2018, 22:40






