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Was the number of books sold at Bookstore X last week greater than the

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Was the number of books sold at Bookstore X last week greater than the  [#permalink]

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New post 16 Jun 2016, 05:18
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Was the number of books sold at Bookstore X last week greater than the number of books sold at Bookstore Y last week?



(1) Last week, more than 1,000 books were sold at Bookstore X on Saturday and fewer than 1,000 books were sold at Bookstore Y on Saturday

(2) Last week, less than 20 percent of the books sold at Bookstore X were sold on Saturday and more than 20 percent of the books sold at Bookstore Y were sold on Saturday

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Re: Was the number of books sold at Bookstore X last week greater than the  [#permalink]

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New post 08 Dec 2016, 09:45
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Bunuel wrote:
Was the number of books sold at Bookstore X last week greater than the number of books sold at Bookstore Y last week?

(1) Last week, more than 1,000 books were sold at Bookstore X on Saturday and fewer than 1,000 books were sold at Bookstore Y on Saturday
(2) Last week, less than 20 percent of the books sold at Bookstore X were sold on Saturday and more than 20 percent of the books sold at Bookstore Y were sold on Saturday


We need to determine whether the number of books sold at Bookstore X last week was greater than the number of books sold at Bookstore Y.

Statement One Alone:

Last week, more than 1,000 books were sold at Bookstore X on Saturday and fewer than 1,000 books were sold at Bookstore Y on Saturday.

Knowing the number of books that were sold on one day of the week is not enough information to determine whether, for the entire week, the number of books sold at Bookstore X was greater than the number of books sold at Bookstore Y. Statement one alone is not sufficient. We can eliminate answer choices A and D.

Statement Two Alone:

Last week, less than 20 percent of the books sold at Bookstore X were sold on Saturday and more than 20 percent of the books sold at Bookstore Y were sold on Saturday.

Since we do not know how many books were sold on Saturday, we cannot determine how many books were sold last week at either Bookstore X or Bookstore Y.

Statements One and Two Together:

Using the information from statements one and two, we can define the following variables:

x = the number of books sold at Bookstore X last week

y = the number of books sold at Bookstore Y last week

s = the number of books sold at Bookstore X on Saturday (note: s > 1,000)

t = the number of books sold at Bookstore Y on Saturday (note: t < 1,000)

p = percent of books at Bookstore X sold last week that were sold on Saturday (note: p < .2)

q = percent of books at Bookstore Y sold last week that were sold on Saturday (note: q > .2)

Using our variables, we can create the following equations:

x = s/p

and

y = t/q

We need to determine whether x > y, or s/p > t/q, or sq > pt. Since s > t and q > p, and all values are positive, we can determine that sq is greater than pt, and thus that x > y.

Answer: C
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Re: Was the number of books sold at Bookstore X last week greater than the  [#permalink]

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New post 16 Jun 2016, 06:01
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A ] Does not tell us anything about the sales in the rest of the week .INSUFFICIENT

B] Does not tell us 20% of what , hence we cannot compare . INSUFFICIENT

Together

Let sales at bookstore X on saturday be 1001 . Therefore >5005 books were sold in the week

Let sales at bookstore Y on saturday be 999. Therefore <4995 books were sold during the week

Hence we can conclude that sales at X were greater than Y for the given week
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Re: Was the number of books sold at Bookstore X last week greater than the  [#permalink]

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New post 04 Jul 2016, 12:12
Q. BooksSoldLW(X) > BooksSoldLW(Y)?
Soln: Stmt1 : Books Sold on Saturday for Bookstore X : >1000. For Store Y: <1000. Not sufficient.
Stmt 2: For Store X: 20% of TotalBooksSoldX > (>1000) => TotalBooksSoldX > [(>1000 x 100)/20]
For store Y: 20% of TotalBooksSoldY < (<1000) => TotalBooksSoldY < [(<1000 x 100/20)]

Clearly Store X Sold more books than Store Y. Hence C.
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Re: Was the number of books sold at Bookstore X last week greater than the  [#permalink]

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New post 04 Jul 2016, 20:02
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Bunuel wrote:
Was the number of books sold at Bookstore X last week greater than the number of books sold at Bookstore Y last week?

(1) Last week, more than 1,000 books were sold at Bookstore X on Saturday and fewer than 1,000 books were sold at Bookstore Y on Saturday
(2) Last week, less than 20 percent of the books sold at Bookstore X were sold on Saturday and more than 20 percent of the books sold at Bookstore Y were sold on Saturday

Totally missed the word Saturday in (1) and thought the sales were for the whole week :drunk :no
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Re: Was the number of books sold at Bookstore X last week greater than the  [#permalink]

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New post 31 Aug 2016, 10:39
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yosita18 wrote:
yosita18 wrote:
Was the number of books sold at Bookstore X last week greater than the number of books sold at Bookstore Y last week?

(1) Last week, more than 1,000 books were sold at Bookstore X on Saturday and fewer than 1,000 books were sold at Bookstore Y on Saturday
(2) Last week, less than 20 percent of the books sold at Bookstore X were sold on Saturday and more than 20 percent of the books sold at Bookstore Y were sold on Saturday

Sir:
The question is asking about the entire week, highlighted in BLUE. But we have been given information for Saturday. How can we conclude about the entire week based on the information provided for Saturday (Only ONE day) ?
Please share your thoughts. Thanks again!


See, Statement 2 is actually talking about the books sold over the entire week. Try Reading it clearly.

It says, Books sold on Saturday represents some some percentage of the entire week books.

Now, try going through the question once again and let us know if you need more clarifications.
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Re: Was the number of books sold at Bookstore X last week greater than the  [#permalink]

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New post 01 Sep 2016, 13:03
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yosita18
I am posting the reply to PM here as it may help others as well.

Let me rephrase the analysis in simpler terms.

Statement 1 : Analysis

Store X: more than 1000 books sold. Say for our consideration, 1001.
Store Y: less than 1000 books sold. Say for our consideration, 999.

This stmt is insufficient since we dont know the sales on other days of the week.

Statement 2: Analysis

Store X: Less than 20% of all the books sold for the week was sold on Saturday. [Say Store X made a sale of 19% of all the books sold over the week.]
Store Y: More than 20% of all the books sold for the week was sold on Saturday. [Say Store Y made a sale of 21% of all the books sold over the week.]

This statement is not sufficient to tell us anything as we cant deduce the accurate figures just on this statement alone.

Combining both the statements:
As going by our example, Store X sold 1001 books which is 19% of overall sales. Therefore, total sale: \(1001 * \frac{100}{19}\)
Similarly, for store Y; total sale: \(999 * \frac{100}{21}\)

Clearly total sales at Bookstore X is more. Hence C.

Hope this helps.
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Re: Was the number of books sold at Bookstore X last week greater than the  [#permalink]

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New post 07 Mar 2017, 14:44
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Was the number of books sold at Bookstore X last week greater than the number of books sold at Bookstore Y last week?

(1) Last week, more than 1,000 books were sold at Bookstore X on Saturday and fewer than 1,000 books were sold at Bookstore Y on Saturday

(2) Last week, less than 20 percent of the books sold at Bookstore X were sold on Saturday and more than 20 percent of the books sold at Bookstore Y were sold on Saturday


OG has the best explanation hands down...

We are looking to answer if Tx > Ty where Tx and Ty represent Total Books x and Total Books Y respectively

Statement (1): Xsat > 1000 and Ysat < 1000 - Insufficient

Statement (2): Xsat < 0.2Tx and Ysat > 0.2Ty - Insufficient


Combining both statements we have:

For Bookstore X: 1000 < Xsat < 0.2Tx this can be simplified 1000 < 0.2Tx divide both sides by 0.2 gives Tx > 5000

For Bookstore Y: 0.2Ty < Ysat < 1000 this can be simplified 1000 > 0.2Ty divide both sides by 0.2 gives Ty < 5000

Therefore C

The take away message from this exercise is that you should know that when you have something like a < x < b then a, x < b which means that you can generate two independent inequalities from a compound inequality with 3 terms (i.e. a < b and x < b) . The rest of the question is simply read carefully and translate the words into maths/equation/inequalities.
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Re: Was the number of books sold at Bookstore X last week greater than the  [#permalink]

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New post 21 Oct 2017, 11:27
Bunuel wrote:
Was the number of books sold at Bookstore X last week greater than the number of books sold at Bookstore Y last week?

(1) Last week, more than 1,000 books were sold at Bookstore X on Saturday and fewer than 1,000 books were sold at Bookstore Y on Saturday
(2) Last week, less than 20 percent of the books sold at Bookstore X were sold on Saturday and more than 20 percent of the books sold at Bookstore Y were sold on Saturday


It is based on application of the basic concept (think irrespective of the question):

" If (50% of A) < (80% of B) , then that would simply mean A<B
If (50% of A) > (80% of B), then that would simply mean A>B"

Coming to the question, take 10% as an example of any number less than 20% and 30% as more than 20%

If 10% of A (more than 1000 : statement 1) > 30% of B (fewer than 1000: statement 2)
this would simply mean A>B

This is what we get by combining 1 & 2.
"C"
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Re: Was the number of books sold at Bookstore X last week greater than the  [#permalink]

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New post 28 Nov 2017, 18:12
I am a little confused. Even if we can solve the whole question based on the information given, how are finding out the number of books sold for the entire week .I marked E because i thought we can only find number of books sold on Saturday only..

JeffTargetTestPrep wrote:
Bunuel wrote:
Was the number of books sold at Bookstore X last week greater than the number of books sold at Bookstore Y last week?

(1) Last week, more than 1,000 books were sold at Bookstore X on Saturday and fewer than 1,000 books were sold at Bookstore Y on Saturday
(2) Last week, less than 20 percent of the books sold at Bookstore X were sold on Saturday and more than 20 percent of the books sold at Bookstore Y were sold on Saturday


We need to determine whether the number of books sold at Bookstore X last week was greater than the number of books sold at Bookstore Y.

Statement One Alone:

Last week, more than 1,000 books were sold at Bookstore X on Saturday and fewer than 1,000 books were sold at Bookstore Y on Saturday.

Knowing the number of books that were sold on one day of the week is not enough information to determine whether, for the entire week, the number of books sold at Bookstore X was greater than the number of books sold at Bookstore Y. Statement one alone is not sufficient. We can eliminate answer choices A and D.

Statement Two Alone:

Last week, less than 20 percent of the books sold at Bookstore X were sold on Saturday and more than 20 percent of the books sold at Bookstore Y were sold on Saturday.

Since we do not know how many books were sold on Saturday, we cannot determine how many books were sold last week at either Bookstore X or Bookstore Y.

Statements One and Two Together:

Using the information from statements one and two, we can define the following variables:

x = the number of books sold at Bookstore X last week

y = the number of books sold at Bookstore Y last week

s = the number of books sold at Bookstore X on Saturday (note: s > 1,000)

t = the number of books sold at Bookstore Y on Saturday (note: t < 1,000)

p = percent of books at Bookstore X sold last week that were sold on Saturday (note: p < .2)

q = percent of books at Bookstore Y sold last week that were sold on Saturday (note: q > .2)

Using our variables, we can create the following equations:

x = s/p

and

y = t/q

We need to determine whether x > y, or s/p > t/q, or sq > pt. Since s > t and q > p, and all values are positive, we can determine that sq is greater than pt, and thus that x > y.

Answer: C
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Re: Was the number of books sold at Bookstore X last week greater than the  [#permalink]

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New post 29 Jan 2018, 05:49
amanvermagmat niks18 chetan2u


Quote:

Was the number of books sold at Bookstore X last week greater than the number of books sold at Bookstore Y last week?

(1) Last week, more than 1,000 books were sold at Bookstore X on Saturday and fewer than 1,000 books were sold at Bookstore Y on Saturday
(2) Last week, less than 20 percent of the books sold at Bookstore X were sold on Saturday and more than 20 percent of the books sold at Bookstore Y were sold on Saturday


I could not understand why ans is C and not E.
The question stem talks about finding no of books in TOTAL WEEK and each statement talks about only SAT.
What if from Mon to Fri book sales are reverse than mentioned in St 2?
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Re: Was the number of books sold at Bookstore X last week greater than the  [#permalink]

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New post 29 Jan 2018, 09:15
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adkikani wrote:
amanvermagmat niks18 chetan2u


Quote:

Was the number of books sold at Bookstore X last week greater than the number of books sold at Bookstore Y last week?

(1) Last week, more than 1,000 books were sold at Bookstore X on Saturday and fewer than 1,000 books were sold at Bookstore Y on Saturday
(2) Last week, less than 20 percent of the books sold at Bookstore X were sold on Saturday and more than 20 percent of the books sold at Bookstore Y were sold on Saturday


I could not understand why ans is C and not E.
The question stem talks about finding no of books in TOTAL WEEK and each statement talks about only SAT.
What if from Mon to Fri book sales are reverse than mentioned in St 2?


Hi

We dont necessarily have to find the total number of books last week for X and Y. All we need is a comparison between books sold at X and books sold at Y last week.

Books at X on Saturday > 1000, and these are less than 20% (or less than 1/5) of books sold in entire week. This means books sold in entire week in X > 5*1000 or number of books in X in entire week > 5000

Also books at Y on Saturday < 1000, and these are more than 20% (1/5) of books sold in entire week. So this number is less than 1000, but more than 1/5 of total week. IF this number was 1000 and exactly equal to 1/5 of total, then the total books would have been = 5*1000 = 5000. But here the books sold in Y in entire week will be less than 5000.

So, even though we are unable to determine the exact number of books sold in X and in Y - we at least know for sure that for X the number is > 5000 and for Y the number is < 5000. Hence Sufficient.
Re: Was the number of books sold at Bookstore X last week greater than the &nbs [#permalink] 29 Jan 2018, 09:15
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