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.

It appears that you are browsing the GMAT Club forum unregistered!

Signing up is free, quick, and confidential.
Join other 500,000 members and get the full benefits of GMAT Club

Registration gives you:

Tests

Take 11 tests and quizzes from GMAT Club and leading GMAT prep companies such as Manhattan GMAT,
Knewton, and others. All are free for GMAT Club members.

Applicant Stats

View detailed applicant stats such as GPA, GMAT score, work experience, location, application
status, and more

Books/Downloads

Download thousands of study notes,
question collections, GMAT Club’s
Grammar and Math books.
All are free!

Thank you for using the timer!
We noticed you are actually not timing your practice. Click the START button first next time you use the timer.
There are many benefits to timing your practice, including:

Stumped on this Data Sufficiency question... [#permalink]

Show Tags

10 Apr 2008, 11:09

This topic is locked. If you want to discuss this question please re-post it in the respective forum.

This question came from math bin 3 in the Princeton Review 2008 book.

If P is a set of integers and 3 is in P, is every positive multiple of 3 in P?

1) For any integer in P, the sum of 3 and that integer is also in P. 2) For any integer in P, that integer minus 3 is also in P.

My reasoning is that each statement alone is sufficient, because...

stmt. 1 - any positive multiple of 3 is included because it could be 0 + 3 = 3, 3 + 3 = 6...., 9 + 3 = 12, etc.

stmt. 2- this could be 3 - 3 = 0, 6 - 3 = 3, and so on. so all positive multiples of 3 should also be included right? According to the PR explanations, statement 2 gives all the negative multiples of 3 and that the correct answer is: statement 1 alone is sufficient, but statement 2 alone is not sufficient.

Is this an error in the book or am I completely overlooking something?

Re: Stumped on this Data Sufficiency question... [#permalink]

Show Tags

10 Apr 2008, 13:28

As per question If P is a set of integers and 3 is in P. Let us assume that to start with P contains only 3.

Statement 1: Tells us that for any integer in P, the sum of 3 and that integer is also in P. As we already have 3 as part of P, so what follows is we have 3+3 = 6, 6+3 =9, 9+3 = 12...... etc. as part of P. So question is answered.

Statement 2: Tells us for any integer in P, that integer minus 3 is also in P. As we already have 3 as part of P, so what follows is we have 3-3 = 0, 0-3 = -3, -3-3 = -6,....etc. as part of P. So question is not answered.

Re: Stumped on this Data Sufficiency question... [#permalink]

Show Tags

10 Apr 2008, 19:46

prasannar wrote:

For any integer in P, the sum of 3 and that integer is also in P.

why are you not considering numbers 1,2,4,5 in Stmt-1

I get it now... the question only confirms that the number 3 is in the set. so only 3, 3+3 or 6, 6+3 or 9, 9+3 or 12, etc. are in this set according to statement 1.

Re: Stumped on this Data Sufficiency question... [#permalink]

Show Tags

11 Apr 2008, 05:31

prasannar wrote:

For any integer in P, the sum of 3 and that integer is also in P.

why are you not considering numbers 1,2,4,5 in Stmt-1

Question is asking abouy whether all the +ve multiples of 3 is present in series or not. Which we can answer from the information present in the question. Even if 1,2 etc. are there that would not add much value in answering the question.

Re: Stumped on this Data Sufficiency question... [#permalink]

Show Tags

11 Apr 2008, 08:59

With the same logic, statement 2 can be proved as well. Not sure why the answer is A . The multiples of 3 may or may not be present in either of the statements.

Ama have to go with E here folks .

Explanation anyone ?

gmatclubot

Re: Stumped on this Data Sufficiency question...
[#permalink]
11 Apr 2008, 08:59