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:

PS: Number Properties [#permalink]
02 Mar 2009, 08:28

00:00

A

B

C

D

E

Difficulty:

(N/A)

Question Stats:

0% (00:00) correct
0% (00:00) wrong based on 0 sessions

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

If n is a multiple of 5 and n=(p^2)*q, where p and q are prime numbers, which of the following must be a multiple of 25? a) p^2 b) q^2 c) pq d) (p^2)*(q^2) e) (p^3)*q

Re: PS: Number Properties [#permalink]
02 Mar 2009, 08:35

My thought process what if n is a multiple of 5 and n = (p^2)*q, where p and q are prime numbers, then q has to be 5 because no prime number squared = 5. So if the question wants to know what number is a multiple of 25? .... then you have to square q. So if q^2 equals 25, then (p^2)*(q^2) has to be a multiple of 25.

The correct answer is D....(p^2)*(q^2), but I wanted to make sure my thought process was correct.

Additionally, one of the answers was q^2. Is 25 technically a multiple of 25? (i.e. 1X25 = 25) Or does a multiple, technically, have to be greater than the number itself?

Re: PS: Number Properties [#permalink]
08 Mar 2009, 03:48

Expert's post

Economist wrote:

Didnt get this..please explain.

1) n is divisible by 5, so p OR q must be 5 (as p and q are prime numbers).

2) to be divisible by 5 a new number must contain p^2 AND q^2. Otherwise, there would be possibility for a new number to be not divisible by 25. _________________