GMAT Question of the Day: Daily via email | Daily via Instagram New to GMAT Club? Watch this Video

It is currently 28 Feb 2020, 17:26

Close

GMAT Club Daily Prep

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.

Close

Request Expert Reply

Confirm Cancel

If z is a multiple of 24, what is the remainder when z^2 is

  new topic post reply Question banks Downloads My Bookmarks Reviews Important topics  
Author Message
TAGS:

Hide Tags

Find Similar Topics 
Manager
Manager
User avatar
Joined: 21 Jul 2009
Posts: 126
Location: New York, NY
If z is a multiple of 24, what is the remainder when z^2 is  [#permalink]

Show Tags

New post Updated on: 17 Sep 2009, 08:07
2
1
00:00
A
B
C
D
E

Difficulty:

  15% (low)

Question Stats:

79% (01:10) correct 21% (01:17) wrong based on 165 sessions

HideShow timer Statistics

If z is a multiple of 24, what is the remainder when z^2 is divided by 9?

(A) 0
(B) 1
(C) 2
(D) 4
(E) 6

Originally posted by mendelay on 04 Sep 2009, 07:24.
Last edited by mendelay on 17 Sep 2009, 08:07, edited 2 times in total.
Director
Director
User avatar
Joined: 04 Jan 2008
Posts: 595
Re: Another remainder question....  [#permalink]

Show Tags

New post 04 Sep 2009, 07:44
is it
A--0?

z=24(K)=2^3(3)(k)

z^2=2^6(9)(k^2)

now z^2/9= 2^6(k^2)==multiple of 2^6

mendelay wrote:
If z is a multiple of 24, what is the remainder when z^2 is divided by 9?

(A) 0
(B) 1
(C) 2
(D) 4
(E) 6

Intern
Intern
avatar
Joined: 27 Aug 2009
Posts: 23
Re: Another remainder question....  [#permalink]

Show Tags

New post 04 Sep 2009, 10:52
24= (8*3)n
the resultant number will be multiplied by 3^2 for sure... hence z^2/9 will have its remiander as 0...

wats the OA?
Manager
Manager
avatar
Joined: 25 Aug 2009
Posts: 130
Re: Another remainder question....  [#permalink]

Show Tags

New post 04 Sep 2009, 13:44
1
this question will hardly take more than 30 seconds..

this is not data sufficiency problem, in which you have to test the answer by plugging different values..

this is problem solving question asking for a definite answer..So, the answer would be same whether z is 24 or any other multiple of 24.

Let z = 24 ; =>\(z^2 = 24*24\)

=>\(z^2 = 9*64\) ( divisible by 9)
Manager
Manager
User avatar
Joined: 22 Dec 2009
Posts: 231
GMAT ToolKit User
Re: Another remainder question....  [#permalink]

Show Tags

New post 31 Jan 2010, 06:21
1
1
mendelay wrote:
If z is a multiple of 24, what is the remainder when z^2 is divided by 9?

(A) 0
(B) 1
(C) 2
(D) 4
(E) 6




z = 24 * K = 8 * 3 * k
z^2 = 8^2 * 9 * k^2

Therefore z^2 Mod 9 = 0 ( as 9 is a factor in the same)

Answer A
Intern
Intern
User avatar
Joined: 17 Nov 2009
Posts: 29
Schools: University of Toronto, Mcgill, Queens
Re: Another remainder question....  [#permalink]

Show Tags

New post 12 Feb 2010, 08:27
jeeteshsingh wrote:
mendelay wrote:
If z is a multiple of 24, what is the remainder when z^2 is divided by 9?

(A) 0
(B) 1
(C) 2
(D) 4
(E) 6




z = 24 * K = 8 * 3 * k
z^2 = 8^2 * 9 * k^2

Therefore z^2 Mod 9 = 0 ( as 9 is a factor in the same)

Answer A


nice explanation but also you can do the other way by calculating square of 24 and then divide by 9.
Director
Director
avatar
Joined: 03 Aug 2012
Posts: 651
Concentration: General Management, General Management
GMAT 1: 630 Q47 V29
GMAT 2: 680 Q50 V32
GPA: 3.7
WE: Information Technology (Investment Banking)
Re: Another remainder question....  [#permalink]

Show Tags

New post 09 Aug 2013, 05:51
Easy one:

Z=24A

Z^2 = 24*24* A^2

REM(24/9) = 6

Rem (Z^2/9) = REM (6*6* A^2)/9
= REM(36*A^2)/9
= REM(0*A^2)/9

=0

Rgds,
TGC!
Senior Manager
Senior Manager
avatar
Joined: 10 Jul 2013
Posts: 279
Re: Another remainder question....  [#permalink]

Show Tags

New post 09 Aug 2013, 10:12
mendelay wrote:
If z is a multiple of 24, what is the remainder when z^2 is divided by 9?

(A) 0
(B) 1
(C) 2
(D) 4
(E) 6



........
z=24k
or, z = 8×3×k
or, z^2 = 64 × 9 × k^2

So remainder is 0 (A)
Intern
Intern
avatar
Joined: 31 Aug 2013
Posts: 12
Re: If z is a multiple of 24, what is the remainder when z^2 is  [#permalink]

Show Tags

New post 17 Nov 2013, 12:15
If z is a multiple of 24, what is the remainder when z^2 is divided by 9?

(A) 0
(B) 1
(C) 2
(D) 4
(E) 6

z =24k

z^2= 24*24
ie 24*24/9 = 64

So,the remainder is 0.

Answer is (a).
SVP
SVP
User avatar
Joined: 06 Sep 2013
Posts: 1514
Concentration: Finance
GMAT ToolKit User
Re: If z is a multiple of 24, what is the remainder when z^2 is  [#permalink]

Show Tags

New post 27 Jan 2014, 04:31
For this problem I just did the following

Took z = 24

Then 24/9 remainder is 6
Do this twice and you will get 6*6 / 9

Remainder of 36/9 is zero

That's your answer

Cheers!
J :)
Math Expert
User avatar
V
Joined: 02 Sep 2009
Posts: 61549
Re: If z is a multiple of 24, what is the remainder when z^2 is  [#permalink]

Show Tags

New post 27 Jan 2014, 05:11
1
Intern
Intern
avatar
Joined: 05 Dec 2013
Posts: 28
Concentration: Technology
GMAT Date: 02-01-2014
GPA: 3.95
WE: Information Technology (Venture Capital)
Re: If z is a multiple of 24, what is the remainder when z^2 is  [#permalink]

Show Tags

New post 27 Jan 2014, 20:22
24 = 2^3 * 3. Any multiple of this could be 2^4 * 3, 2^3 *3^2, etc.

Let's assume z = 24 for now. So z = 2^3 * 3. Then z^2 = 2^6 * 3^2. If we divide this by 9 or 3^2 we will end up with no denominator, meaning there is no remainder.
Non-Human User
User avatar
Joined: 09 Sep 2013
Posts: 14155
Re: If z is a multiple of 24, what is the remainder when z^2 is  [#permalink]

Show Tags

New post 06 Jan 2020, 07:26
Hello from the GMAT Club BumpBot!

Thanks to another GMAT Club member, I have just discovered this valuable topic, yet it had no discussion for over a year. I am now bumping it up - doing my job. I think you may find it valuable (esp those replies with Kudos).

Want to see all other topics I dig out? Follow me (click follow button on profile). You will receive a summary of all topics I bump in your profile area as well as via email.
_________________
GMAT Club Bot
Re: If z is a multiple of 24, what is the remainder when z^2 is   [#permalink] 06 Jan 2020, 07:26
Display posts from previous: Sort by

If z is a multiple of 24, what is the remainder when z^2 is

  new topic post reply Question banks Downloads My Bookmarks Reviews Important topics  





Powered by phpBB © phpBB Group | Emoji artwork provided by EmojiOne