Author 
Message 
TAGS:

Hide Tags

Math Expert
Joined: 02 Sep 2009
Posts: 61302

Each gift certificate sold yesterday by a certain bookstore
[#permalink]
Show Tags
08 Oct 2012, 01:49
Question Stats:
71% (02:12) correct 29% (02:03) wrong based on 1790 sessions
HideShow timer Statistics
Each gift certificate sold yesterday by a certain bookstore cost either $10 or $50. If yesterday the bookstore sold more than 5 gift certificates that cost $50 each, what was the total number of gift certificates sold yesterday by the bookstore? (1) Yesterday the bookstore sold fewer than 10 gift certificates that cost $10 each. (2) The total cost of gift certificates sold yesterday by the bookstore was $460. Practice Questions Question: 57 Page: 279 Difficulty: 600
Official Answer and Stats are available only to registered users. Register/ Login.
_________________




Math Expert
Joined: 02 Sep 2009
Posts: 61302

Re: Each gift certificate sold yesterday by a certain bookstore
[#permalink]
Show Tags
08 Oct 2012, 01:50
SOLUTIONEach gift certificate sold yesterday by a certain bookstore cost either $10 or $50. If yesterday the bookstore sold more than 5 gift certificates that cost $50 each, what was the total number of gift certificates sold yesterday by the bookstore?Let x be the number of $10 gift certificates and y be the number of $50 gift certificates. Given: y > 5. Question: x + y = ?. (1) Yesterday the bookstore sold fewer than 10 gift certificates that cost $10 each. x<10. clearly insufficient. (2) The total cost of gift certificates sold yesterday by the bookstore was $460. 10x+50y=460. Several pairs are possible: for example x=1 and y=9 as well as x=6 and y=8. Not sufficient. (1)+(2) x=1 and y=9 as well as x=6 and y=8 satisfy both statements. Not sufficient. Answer: E.
_________________




Senior Manager
Joined: 15 Jun 2010
Posts: 269
Schools: IE'14, ISB'14, Kellogg'15
WE 1: 7 Yrs in Automobile (Commercial Vehicle industry)

Re: Each gift certificate sold yesterday by a certain bookstore
[#permalink]
Show Tags
08 Oct 2012, 02:15
Let x be $10 Certificate & y be $50 Certificate, We need to find value of x+y=? ST1: Insufficient: SInce x<10, x can take any value from 0 to 9 & Since y >5, y can take any value greater than 5. So x+y will have multiple values. ST2: Insufficient: Given: 10x+50y =460, x>5, So multiple combination can satisfy this equation, for example (x,y) = (9,1), (8,6),..... 1+2: Still insufficient for above reason in ST2. Hence answer E.



Senior Manager
Joined: 24 Aug 2009
Posts: 433
Schools: Harvard, Columbia, Stern, Booth, LSB,

Re: Each gift certificate sold yesterday by a certain bookstore
[#permalink]
Show Tags
08 Oct 2012, 02:26
Let the no of $10 & $50 certificates is x & y respectively Question is x+y=? Given y>5 Note: x & y can only take positive integer values 1) x<10 > Not sufficient 2) 10x + 50y = 460 > x + 5y = 46 Possible values of (x & y) are (16,6), (11,7), (6,8) ,(1,9) >Insufficient 1+2) Given x<10 & y>5 , possible pairs are (6,8) ,(1,9) > No unique value >Insufficient Answer E



Senior Manager
Joined: 31 Oct 2011
Posts: 476
WE: Asset Management (Mutual Funds and Brokerage)

Re: Each gift certificate sold yesterday by a certain bookstore
[#permalink]
Show Tags
08 Oct 2012, 04:13
Let Y = # of gift certificates sold with a value of 50. Let X = # of gift certificates sold with a value of 10. Y > 5 Find X + Y1) X < 10 The solution could be 16X + 6Y = 460 or it could be 6X + 9Y = 390 Insufficient2) 10X + 50Y = 460 The solution could be 16X + 6Y = 460 or it could be 1X + 9Y = 460 InsufficientCombining 1 + 2 X < 10, 10X + 50Y = 460 The solution could be 1X + 9Y = 460 (Total of 10) or it could be 16X + 6Y = 460 (Total of 22) Insufficient
_________________
My Applicant Blog: http://hamm0.wordpress.com/



Manager
Joined: 22 Dec 2011
Posts: 207

Re: Each gift certificate sold yesterday by a certain bookstore
[#permalink]
Show Tags
09 Oct 2012, 06:14
Bunuel wrote: The Official Guide for GMAT® Review, 13th Edition  Quantitative Questions ProjectEach gift certificate sold yesterday by a certain bookstore cost either $10 or $50. If yesterday the bookstore sold more than 5 gift certificates that cost $50 each, what was the total number of gift certificates sold yesterday by the bookstore? (1) Yesterday the bookstore sold fewer than 10 gift certificates that cost $10 each. (2) The total cost of gift certificates sold yesterday by the bookstore was $460. let x be the nos of 10$ copies and y be nos of 50$ copies so x10 + y50 = some value stem also says y>5 Question x+y = ? Statement 1/ x<10 (from stem y>5) many combinations are possible for x+y so NS Statment 2/ x10 + y50 = 460 As y> 5 then we can find out the possible values for x x10 + 300 = 460 ............ when y = 6 then x=16 x10 + 350 = 460 ................. y=7 then x=11 x10 + 400 = 460..................y=8 then x=6 x10 + 450 = 460 .............y=9 then x=1 on solving above we can get x = 16,11,6,1 Nt sufficient to calcuate value of x+y Combined we know y>5 and x <10 even then we have 2 value pairs for (x,y) = (6,8) (1,9) so E



Manager
Joined: 16 Feb 2012
Posts: 142
Concentration: Finance, Economics

Re: Each gift certificate sold yesterday by a certain bookstore
[#permalink]
Show Tags
09 Oct 2012, 08:30
Each gift certificate sold yesterday by a certain bookstore cost either $10 or $50. If yesterday the bookstore sold more than 5 gift certificates that cost $50 each, what was the total number of gift certificates sold yesterday by the bookstore?
(1) Yesterday the bookstore sold fewer than 10 gift certificates that cost $10 each. (2) The total cost of gift certificates sold yesterday by the bookstore was $460.
Statement 1: Insufficient We don't know the exact number of gift certificates sold, there could be more than one solution. Statement 2: Insufficient Same as in the statement 1, there could be one 10$ gift certificate and nine 50$ gift certificates...or sixteen 10$ gift certificates and six 50$ gift certificates.
Together statements don't provide the solution, so the answer is E.



Manager
Joined: 12 Jan 2013
Posts: 139

Re: Each gift certificate sold yesterday by a certain bookstore
[#permalink]
Show Tags
10 Jan 2014, 07:36
Bunuel wrote: Each gift certificate sold yesterday by a certain bookstore cost either $10 or $50. If yesterday the bookstore sold more than 5 gift certificates that cost $50 each, what was the total number of gift certificates sold yesterday by the bookstore? (1) Yesterday the bookstore sold fewer than 10 gift certificates that cost $10 each. (2) The total cost of gift certificates sold yesterday by the bookstore was $460. Practice Questions Question: 57 Page: 279 Difficulty: 600 We are given the equation: 10*x + 50*y = Total Sales, by the stem. Also, we're given the restriction y > 5. 1) Gives us the restriction x < 10, but as we have absolutely no idea what total sales are, theoretically we have almost infinite possibilities (and even with TS it would be insufficient). Insufficient. 2) Solves one of our three unknowns, so clearly insufficient.. If we combine the two, the only thing we know is that 10*10 + 5*50 is not a possible value (neither are certain other combinations of x and y), and that the total sales = 460.. So, 10*x + 5*y = 460.. This means that the difference could be more/less than 110 (because of 10*10 + 5*50 = 110 not being a possible combination) .. And we could combine x and y in many different ways to arrive at 110, for instance 11x's and no y's, or 2y's and 1 x... And even at that, we still only have a vague, nondefinite relation between X and Y, even though we have solved for Total Sales. So all in all, the stem + the two statements really only give us a weak restriction for X and Y, and solve for total sales.. So we still have 2 unknowns that we need to solve for, and thus the info is insufficient.. Our answer is E.



Intern
Joined: 30 Dec 2013
Posts: 15

Re: Each gift certificate sold yesterday by a certain bookstore
[#permalink]
Show Tags
22 Feb 2015, 10:43
Hi BB. You are doing great job. Salute. Is this question really 700 level? OG is said to be in increasing difficulty order so how can Q.57 be level 700 question? Respectfully, Verve42



Math Expert
Joined: 02 Sep 2009
Posts: 61302

Re: Each gift certificate sold yesterday by a certain bookstore
[#permalink]
Show Tags
22 Feb 2015, 10:51
Verve42 wrote: Hi BB. You are doing great job. Salute. Is this question really 700 level? OG is said to be in increasing difficulty order so how can Q.57 be level 700 question? Respectfully, Verve42 Thank you! But I'm not BB. BB is completely different person: members/member3.htmlAs for the difficulty level of this question: it's calculated based on the Timer (check the original post) and according to sessions of 356 users, it is a 700 question.
_________________



Manager
Joined: 05 Nov 2014
Posts: 97
Location: India
Concentration: Strategy, Operations
GPA: 3.75

Re: Each gift certificate sold yesterday by a certain bookstore
[#permalink]
Show Tags
20 Jun 2017, 05:55
Bunuel wrote: Each gift certificate sold yesterday by a certain bookstore cost either $10 or $50. If yesterday the bookstore sold more than 5 gift certificates that cost $50 each, what was the total number of gift certificates sold yesterday by the bookstore? (1) Yesterday the bookstore sold fewer than 10 gift certificates that cost $10 each. (2) The total cost of gift certificates sold yesterday by the bookstore was $460. Practice Questions Question: 57 Page: 279 Difficulty: 600 Statement 1: It doesn't provide any useful information on its own to solve the problem. Knowing fewer than 10 certificates of cost $10 is not enough to answer the problem. Statement 2: We can have 8 number of $50 and 6 number of $10 or we can have 9 number of $50 and 1 number of $10. Combining both, we don't get a unique solution,we still have 2 valid choices. So the answer is E



Target Test Prep Representative
Status: Head GMAT Instructor
Affiliations: Target Test Prep
Joined: 04 Mar 2011
Posts: 2801

Re: Each gift certificate sold yesterday by a certain bookstore
[#permalink]
Show Tags
06 Jul 2017, 17:21
Bunuel wrote: Each gift certificate sold yesterday by a certain bookstore cost either $10 or $50. If yesterday the bookstore sold more than 5 gift certificates that cost $50 each, what was the total number of gift certificates sold yesterday by the bookstore?
(1) Yesterday the bookstore sold fewer than 10 gift certificates that cost $10 each. (2) The total cost of gift certificates sold yesterday by the bookstore was $460. We can let x = the number of $10 gift certificates and y = the number of $50 gift certificates. Thus, we know that y > 5. We need to determine the value of x + y. Statement One Alone: Yesterday the bookstore sold fewer than 10 gift certificates that cost $10 each. Using the information in statement one, we know that x < 10. Without knowing the exact values of x and y, statement one alone is not sufficient to answer the question. Statement Two Alone: The total cost of gift certificates sold yesterday by the bookstore was $460. We can create the following equation: 10x + 50y = 460 x + 5y = 46 We see that y could be 8 and x could be 6, or y could be 9 and x could be 1. In one case, x + y is 14, and in the other, x + y is 10. Therefore, we do not have a definitive value for x + y. Statement two alone is not sufficient to answer the question. Statements One and Two Together: Using the given information, we see that: y > 5 x < 10 x + 5y = 46 Furthermore, x and y are integers. We can substitute integer values for y (as long as it satisfies the first inequality) and check whether these values will also satisfy the other inequality and equation. For example: If y = 6, then x = 16 (using the equation x + 5y = 46). But, then x is not less than 10, so y can’t be 6. If y = 7, then x = 11. Again, x is not less than 10, so y can’t be 7. If y = 8, then x = 6. We see that x is less than 10. So y can be 8 and x will be 6. If y = 9, then x = 1. We see that x is less than 10, so y can be 9 and x will be 1. However, we have two different values each for x and y, adding up to different values. Both statements together still are not sufficient to answer the question. Answer: E
_________________
5star rated online GMAT quant self study course See why Target Test Prep is the top rated GMAT quant course on GMAT Club. Read Our Reviews
If you find one of my posts helpful, please take a moment to click on the "Kudos" button.



EMPOWERgmat Instructor
Status: GMAT Assassin/CoFounder
Affiliations: EMPOWERgmat
Joined: 19 Dec 2014
Posts: 16118
Location: United States (CA)

Re: Each gift certificate sold yesterday by a certain bookstore
[#permalink]
Show Tags
14 Dec 2017, 15:20
Hi All, We're told that Each gift certificate sold yesterday cost either $10 or $50 and that the bookstore sold MORE than 5 gift certificates that cost $50 each. We're asked for the total number of gift certificates sold yesterday by the bookstore. This question can be solved by TESTing VALUES. 1) Yesterday the bookstore sold fewer than 10 gift certificates that cost $10 each. Fact 1 tells us that there could be from 010 $10 certificates and 6 or more $50 certificates, but we don't know the TOTAL certificates sold. Fact 1 is INSUFFICIENT 2) The total cost of gift certificates sold yesterday by the bookstore was $460. IF... 8 $50 certificates and 6 $10 certificates were sold, then the answer to the question is 14. 9 $50 certificates and 1 $10 certificates were sold, then the answer to the question is 10. Fact 2 is INSUFFICIENT Combined, we already have two TESTs that 'fit' both Facts and provide different results: 8 $50 certificates and 6 $10 certificates were sold, then the answer to the question is 14. 9 $50 certificates and 1 $10 certificates were sold, then the answer to the question is 10. Combined, INSUFFICIENT Final Answer: GMAT assassins aren't born, they're made, Rich
_________________
Contact Rich at: Rich.C@empowergmat.comThe Course Used By GMAT Club Moderators To Earn 750+ souvik101990 Score: 760 Q50 V42 ★★★★★ ENGRTOMBA2018 Score: 750 Q49 V44 ★★★★★



NonHuman User
Joined: 09 Sep 2013
Posts: 14100

Re: Each gift certificate sold yesterday by a certain bookstore
[#permalink]
Show Tags
22 Jan 2020, 07:29
Hello from the GMAT Club BumpBot! Thanks to another GMAT Club member, I have just discovered this valuable topic, yet it had no discussion for over a year. I am now bumping it up  doing my job. I think you may find it valuable (esp those replies with Kudos). Want to see all other topics I dig out? Follow me (click follow button on profile). You will receive a summary of all topics I bump in your profile area as well as via email.
_________________




Re: Each gift certificate sold yesterday by a certain bookstore
[#permalink]
22 Jan 2020, 07:29






