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

 It is currently 20 Aug 2018, 14:01

### 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

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

# A total of 100 customers purchased books at a certain

Author Message
Manager
Joined: 10 Oct 2008
Posts: 56
A total of 100 customers purchased books at a certain  [#permalink]

### Show Tags

08 Nov 2008, 18:21
A total of 100 customers purchased books at a certain bookstore last week. If these customers purchased a total of 200 books, how many of the customers purchased only 1 book each?
(1) None of the customers purchased more than 3 books.
(2) 20 of the customers purchased only 2 books each.

A. Statement (1) ALONE is sufficient, but statement (2) alone is not sufficient.
B. Statement (2) ALONE is sufficient, but statement (1) alone is not sufficient.
C. BOTH statements TOGETHER are sufficient, but NEITHER statement ALONE is sufficient.
D. EACH statement ALONE is sufficient.
E. Statements (1) and (2) TOGETHER are NOT sufficient.

--== Message from GMAT Club Team ==--

This is not a quality discussion. It has been retired.

If you would like to discuss this question please re-post it in the respective forum. Thank you!

To review the GMAT Club's Forums Posting Guidelines, please follow these links: Quantitative | Verbal Please note - we may remove posts that do not follow our posting guidelines. Thank you.
Intern
Joined: 04 Nov 2008
Posts: 15
Re: customers and books ---29  [#permalink]

### Show Tags

08 Nov 2008, 18:34
Jcpenny wrote:
A total of 100 customers purchased books at a certain bookstore last week. If these customers purchased a total of 200 books, how many of the customers purchased only 1 book each?
(1) None of the customers purchased more than 3 books.
(2) 20 of the customers purchased only 2 books each.

A. Statement (1) ALONE is sufficient, but statement (2) alone is not sufficient.
B. Statement (2) ALONE is sufficient, but statement (1) alone is not sufficient.
C. BOTH statements TOGETHER are sufficient, but NEITHER statement ALONE is sufficient.
D. EACH statement ALONE is sufficient.
E. Statements (1) and (2) TOGETHER are NOT sufficient.

let us assume that C1 = consumners who purchased 1 Book
similarly C2= consumners who purchased 2 Books
C3 , C3 , ........

from the equation

1*C1 + 2*C2 + 3*C3 + ........= 200 ---------(1)

C1 + C2 + C3 + C4 + ...........=100 ----------(2)

Now let us test (I)
if no consumer purchased more than 3 books then our equations (1) and (2) will be

1*C1 + 2*C2 + 3*C3 = 200 ---------(1)
C1 + C2 + C3 = 100 ----------(2)

3 unknowens with 2 equation
---Insufficient

test (II)
we will get another equation which is
C2 = 20

however we have unlimited variables C1, C2, C3, C4 .......

test (I) and (II) together

we will have 3 equation and 3 unknowens
1*C1 + 2*C2 + 3*C3 = 200 ---------(1)
C1 + C2 + C3 = 100 ----------(2)
C2 = 20-----------------(3)

which is sufficient

so solution is (c)
VP
Joined: 05 Jul 2008
Posts: 1328
Re: customers and books ---29  [#permalink]

### Show Tags

08 Nov 2008, 18:41
Agree did the same

x+y+z = 100

(1) says 3x+ 2y + z =200

2 eq's 3 unknowns ,Insuff

(2) says 2y=40

x+z 80 Insuff

Together, 3 unknowns, 3 eqs can find x.

--== Message from GMAT Club Team ==--

This is not a quality discussion. It has been retired.

If you would like to discuss this question please re-post it in the respective forum. Thank you!

To review the GMAT Club's Forums Posting Guidelines, please follow these links: Quantitative | Verbal Please note - we may remove posts that do not follow our posting guidelines. Thank you.
Re: customers and books ---29 &nbs [#permalink] 08 Nov 2008, 18:41
Display posts from previous: Sort by

# A total of 100 customers purchased books at a certain

Moderator: chetan2u

# Events & Promotions

 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®.