Advanced PS Question Pack1 Question

Post your questions about customer service issues, GMAT exam policies, and GMAT exam structure. Get an official answer from GMAC, the organization behind the GMAT test!
This topic has expert replies
User avatar
Master | Next Rank: 500 Posts
Posts: 192
Joined: Wed Jul 11, 2012 5:04 pm
Thanked: 20 times
Followed by:5 members
GMAT Score:650

Advanced PS Question Pack1 Question

by bpolley00 » Tue Aug 13, 2013 5:45 pm
For a certain set of numbers, If x is in the set, then x-3 is also in the set. If the number 1 is in the set, which of the following must also be in the set?
I. 4
II. -1
III. -5

I only
II only
III only
I and II
II and III

GMAT Question Pack Explanation: It is given that 1 is in the set. Therefore 1-3= -2 is in the set. Since we know -2 is in the set then -5 is also in the set. This set doesn't contain 4 or -1!. Therefore it is not true 4 or -1 must be in the set.

I was hoping GMAT would address an issue I found with this particular problem.
The general issue is this: The set doesn't necessarily need ANY of the numbers listed above following the logic in the answer explanation. Here is an example Let's say X = 1 and therefore the second variable x-3 would equal -2. The set could merely be (1,-2), thus the answer would be none.No where in the question does it implicitly state the set is more than 2 numbers nor does it state that it must be continuous. However, following the question and assuming that it needs to have one, I believe the better answer would be I. Was X=4, therefore X-3 = 1 so the set would have to be {4,1}

Any thoughts on this? I bought the question pack and it has been immensely helpful, so thank you; however, I just spotted this question and there has been a few questions that I have found kind of worrisome so I appreciate your response on this.

-BP

User avatar
Official Company Rep
Posts: 669
Joined: Tue Jun 12, 2012 9:06 pm
Location: Washington DC
Thanked: 143 times
Followed by:270 members
GMAT Score:800

by OfficialGMAT » Wed Aug 14, 2013 11:17 am
Hello, BP.I have passed your question on to our GMATPrep team. If you send an email to [email protected] they can get back to you with a detailed response.

Thank you!

Rebecca
Leah
Official GMAC Representative

Have a question about customer service issues, GMAT exam policies, or GMAT exam structure? Post your question in our Ask the Test Maker forum!

User avatar
Master | Next Rank: 500 Posts
Posts: 192
Joined: Wed Jul 11, 2012 5:04 pm
Thanked: 20 times
Followed by:5 members
GMAT Score:650

by bpolley00 » Wed Aug 14, 2013 4:47 pm
Rebecca,

The e-mail has been sent. I have my test tomorrow so it doesn't really matter much for me; however, I thought it may be helpful to other students! Thanks so much for your time.

Sincerely,

BP

User avatar
Official Company Rep
Posts: 669
Joined: Tue Jun 12, 2012 9:06 pm
Location: Washington DC
Thanked: 143 times
Followed by:270 members
GMAT Score:800

by OfficialGMAT » Thu Aug 15, 2013 5:28 am
Thanks for letting us know. I know they are looking into this particular question right now. We always appreciate feedback.

Rebecca
Leah
Official GMAC Representative

Have a question about customer service issues, GMAT exam policies, or GMAT exam structure? Post your question in our Ask the Test Maker forum!