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:

I could not help it.
After I have posted my previous reply I have checked in my Kaplan 2003 book.

The correct answer given is E.

Kaplan:
From the question stem: All we know is that x is a prime number. We want enough information to determine which prime number x is. Our method, then, is to try to find more than one prime that fits with whatever information we're given. If we can, the information is insufficient; if we can't - if we can find only one prime that fits with the information - then the information is sufficient.

1) Insufficient: if x < 15, x could be 2, 3, 5, 7, 11 or 13. Eliminate A and D.
2) Insufficient: if (x-2) is a multiple of five, then x is 2 more than a multiple of 5. So the question is: Can we find more than one prime number that is 2 more than a multiple of five? Yes. Multiples of 5 are 0, 5, 10, 15, 20, and so on. Two more than 5 is 7 - a prime number. While 2 more than 10 is 12, which isn't a prime number, 2 more than 15 is 17, which is prime. Eliminate B.

In combination: Statement 1 narrowed down the possible values of x to 2, 3, 5, 7, 11 and 13. Remember that 0 is a multiple of 5 as well. So both 2 and 7 are more than a multiple of 5, so we cannot find a single answer to the question using both statements. Choose E.

Amit_drummer, I am not sure which Kaplan Book you use. This is the info from the 2003 book.

Good one. I have seen these too (actually I missed out 2 and chose C, when I first solved this problem).

When we think of multiples of 5, all we think of is 5, 10, 15, ...
It can be ..., -15, -10, -5, 0, 5, 10, 15, ...
(though negative is not relavent to this problem)

0 is not a multiple of 5 or for that matter any integer.

in that case the LCM of any 2 numbers, will be a 0.

Multiples mean more than ZERO. 1x, 2x, 3x,....etc.

Zero is considered to be a multiple. I believe the LCM is defined to be a positive number. If not, the LCM would be negative infinity since there are an unlimited number of negative numbers that are multiples of two numbers.
_________________

Best,

AkamaiBrah Former Senior Instructor, Manhattan GMAT and VeritasPrep Vice President, Midtown NYC Investment Bank, Structured Finance IT MFE, Haas School of Business, UC Berkeley, Class of 2005 MBA, Anderson School of Management, UCLA, Class of 1993

0 is not a multiple of 5 or for that matter any integer.

in that case the LCM of any 2 numbers, will be a 0.

Multiples mean more than ZERO. 1x, 2x, 3x,....etc.

Zero is considered to be a multiple. I believe the LCM is defined to be a positive number. If not, the LCM would be negative infinity since there are an unlimited number of negative numbers that are multiples of two numbers.