Find all School-related info fast with the new School-Specific MBA Forum

 It is currently 28 Apr 2016, 19:16

### 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

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

# Events & Promotions

###### Events & Promotions in June
Open Detailed Calendar

# For all positive integers m, [m]=3m when m is odd and [m]=

 Question banks Downloads My Bookmarks Reviews Important topics
Author Message
TAGS:

### Hide Tags

Manager
Joined: 04 Oct 2005
Posts: 246
Followers: 1

Kudos [?]: 43 [2] , given: 0

For all positive integers m, [m]=3m when m is odd and [m]= [#permalink]

### Show Tags

10 Nov 2005, 05:57
2
KUDOS
2
This post was
BOOKMARKED
00:00

Difficulty:

45% (medium)

Question Stats:

51% (01:39) correct 49% (00:37) wrong based on 212 sessions

### HideShow timer Statictics

For all positive integers m, [m]=3m when m is odd and [m]=(1/2)m when m is even. Which of the following is equivalent to [9] * [6]?

A) [81]
B) [54]
C) [36]
D) [27]
E) [18]

OPEN DISCUSSION OF THIS QUESTION IS HERE: for-all-positive-integers-m-3m-when-m-is-odd-125937.html?hilit=equivalent
[Reveal] Spoiler: OA

Attachments

File comment: Spoiler Image

GPrep_m_embedded_in_a_box.jpg [ 26.15 KiB | Viewed 3299 times ]

Manager
Joined: 28 Jun 2005
Posts: 217
Followers: 1

Kudos [?]: 3 [0], given: 0

### Show Tags

10 Nov 2005, 06:16
D
9=3*9
6=1/2*6

9*6= 3*9*3=81

Take D 27=3*27=81
Current Student
Joined: 29 Jan 2005
Posts: 5239
Followers: 23

Kudos [?]: 273 [0], given: 0

### Show Tags

10 Nov 2005, 06:51
For all positive integers m, m = 3m when m is odd and m = (1/2)m when m is even. Which of the following is equivalent to 9 x 6 ?

(A)

9 is odd so 9*3=27.
6 is even so 6/2=3.
27*3=81

Surely I must be overlooking something...
SVP
Joined: 28 May 2005
Posts: 1723
Location: Dhaka
Followers: 7

Kudos [?]: 163 [0], given: 0

### Show Tags

10 Nov 2005, 13:27
up 81 =27* 3

so 27 is the answer.

so D it is.
_________________

hey ya......

Manager
Joined: 04 Oct 2005
Posts: 246
Followers: 1

Kudos [?]: 43 [0], given: 0

### Show Tags

10 Nov 2005, 14:05
OA is D

Manager
Joined: 05 Oct 2005
Posts: 200
Followers: 1

Kudos [?]: 4 [0], given: 0

### Show Tags

10 Nov 2005, 18:13
Pretty confusing exercise!!! I would have say A as well
seems there is a trap here can anyone explain why it is 27

Thanks
_________________

when there is a will there is a way

best regards

SVP
Joined: 16 Oct 2003
Posts: 1811
Followers: 4

Kudos [?]: 90 [2] , given: 0

### Show Tags

10 Nov 2005, 18:36
2
KUDOS
mand-y wrote:
:? Pretty confusing exercise!!! I would have say A as well
seems there is a trap here can anyone explain why it is 27

Thanks

Remember the answer also has underline so you have to tailor the answer to that

81 = 3 * 27 (odd)

hence 27
Intern
Joined: 28 Aug 2006
Posts: 14
Followers: 0

Kudos [?]: 0 [0], given: 0

GMAT Prep - confusing question [#permalink]

### Show Tags

19 Oct 2006, 21:15
For all positive integers M, [M] = 3M when M is odd and [M] = 1/2M when M is even. Which of the following is equivalent to [9] * [6]?

Choices: A) 81 B) 54 C) 36 D) 27 E) 18

How is the answer not 81?
Senior Manager
Joined: 08 Jun 2006
Posts: 340
Location: Washington DC
Followers: 1

Kudos [?]: 36 [0], given: 0

### Show Tags

19 Oct 2006, 21:34
it is possible only when [M] = 1/2 * M = M / 2 when M is even
Intern
Joined: 28 Aug 2006
Posts: 14
Followers: 0

Kudos [?]: 0 [0], given: 0

### Show Tags

19 Oct 2006, 21:51
right, I agree...it is given in the instructions...[M] = M/2 when M is even...i guess I am confused about the order of operations...if you do the dictated operations FIRST then you get 81...if you multiply 9 times 6 First then you get 54 which is even and then taking half you get 27 which is apparently the right answer. I think it is poorly worded or a mistake. There is nothing to indicate that you need to do the multiplication first.

I guess there are a lot of questions like this...where you get some kind of rule imposed on numbers, and i always thought that takes precedence over regular operations.
Director
Joined: 10 Oct 2005
Posts: 720
Followers: 3

Kudos [?]: 15 [0], given: 0

Re: GMAT Prep - confusing question [#permalink]

### Show Tags

19 Oct 2006, 22:07
primeminister wrote:
For all positive integers M, [M] = 3M when M is odd and [M] = 1/2M when M is even. Which of the following is equivalent to [9] * [6]?

Choices: A) 81 B) 54 C) 36 D) 27 E) 18

How is the answer not 81?

[9]M is odd so [M] = 3M-->9*3=27
[6]M is even so [M] = 1/2M-->6/2=3
27*3=81
Hope this helps
_________________

IE IMBA 2010

Intern
Joined: 28 Aug 2006
Posts: 14
Followers: 0

Kudos [?]: 0 [0], given: 0

### Show Tags

19 Oct 2006, 22:22
Yurik I fully agree with you. The official answer according to GMATprep is 27. That is why i was confused. Thanks
Manager
Joined: 13 Sep 2006
Posts: 212
Followers: 2

Kudos [?]: 1 [0], given: 0

### Show Tags

20 Oct 2006, 06:24
primeminister wrote:
Yurik I fully agree with you. The official answer according to GMATprep is 27. That is why i was confused. Thanks

exactly.. I got this question wrong too because of incorrect order of operations..

would someone explain?
Senior Manager
Joined: 13 Sep 2006
Posts: 281
Location: New York
Followers: 1

Kudos [?]: 10 [0], given: 0

Re: GMAT Prep - confusing question [#permalink]

### Show Tags

20 Oct 2006, 08:58
primeminister wrote:
For all positive integers M, [M] = 3M when M is odd and [M] = 1/2M when M is even. Which of the following is equivalent to [9] * [6]?

Choices: A) 81 B) 54 C) 36 D) 27 E) 18

How is the answer not 81?

There is somthing wrong with this question unless I missing something.

1) Say you do what the problem asks:
[9]=3(9)
= 27

AND

[6]=1/2(6)
=3

3 x 27 = 81

2) Now say you misread the question and confused the formulas for even and odd you still get the same answer:

[6]=3(6)
=18

AND

[9]=1/2(9)
=4.5

4.5 x 18 = 81

Ideas anyone?
_________________

"Never let the fear of striking out get in your wayâ€

SVP
Joined: 05 Jul 2006
Posts: 1512
Followers: 5

Kudos [?]: 194 [0], given: 39

### Show Tags

20 Oct 2006, 10:50
For all positive integers M, [M] = 3M when M is odd and [M] = 1/2M when M is even. Which of the following is equivalent to [9] * [6]?

Choices: A) 81 B) 54 C) 36 D) 27 E) 18

[9]*[6] = 27* 3 = 81

[X] = 81 SO X = 81/3 ( BECAUSE X HAS TO BE INTIGER AND 81 IS NOT DEVISIBLE BY TWO)

THUS

X = 27 AND [27] = 3*27 = 81

mY ANSWER IS D
Manager
Joined: 01 Oct 2006
Posts: 242
Followers: 1

Kudos [?]: 6 [0], given: 0

Re: GMAT Prep - confusing question [#permalink]

### Show Tags

20 Oct 2006, 11:14
primeminister wrote:
For all positive integers M, [M] = 3M when M is odd and [M] = 1/2M when M is even. Which of the following is equivalent to [9] * [6]?

Choices: A) 81 B) 54 C) 36 D) 27 E) 18

How is the answer not 81?

Shouldn't the answer be D only when choice D is [27] and not 27? Is there a mistake in the answer choices? should the choices be: A) [81] B) [54] C) [36] D) [27] E) [18]
Director
Joined: 10 Oct 2005
Posts: 720
Followers: 3

Kudos [?]: 15 [0], given: 0

### Show Tags

21 Oct 2006, 10:54
yezz wrote:
For all positive integers M, [M] = 3M when M is odd and [M] = 1/2M when M is even. Which of the following is equivalent to [9] * [6]?

Choices: A) 81 B) 54 C) 36 D) 27 E) 18

[9]*[6] = 27* 3 = 81

[X] = 81 SO X = 81/3 ( BECAUSE X HAS TO BE INTIGER AND 81 IS NOT DEVISIBLE BY TWO)

THUS

X = 27 AND [27] = 3*27 = 81

mY ANSWER IS D

yezz did you meen A?
81 is A and D is 27
_________________

IE IMBA 2010

Director
Joined: 11 Sep 2006
Posts: 514
Followers: 2

Kudos [?]: 35 [0], given: 0

### Show Tags

21 Oct 2006, 11:14
I just did this question on a GMAT prep test, and the answer choices are in brackets, indicating that the answers themselves are subject to the function listed in the question (the function is also in brackets). So since the answer is 81, and 81 is odd, then it's answer D, because [27] means you multiply 27 by 3, which is 81.
_________________

...there ain't no such thing as a free lunch...

Manager
Joined: 04 Oct 2006
Posts: 122
Location: Florida, Argentina, UK
Followers: 2

Kudos [?]: 2 [0], given: 0

### Show Tags

21 Oct 2006, 11:19
guys, the question is not asking for the result of [9] * [6], but its equivalent (which of the following answers, when multiplied by 3 or divided by 2, equals 81 too). I hope this helps.

Choices: A) 81 B) 54 C) 36 D) 27 E) 18

[9]*[6] = 27* 3 = 81

[X] = 81 SO X = 81/3 ( BECAUSE X HAS TO BE INTIGER AND 81 IS NOT DEVISIBLE BY TWO)

THUS

X = 27 AND [27] = 3*27 = 81 from yess
Intern
Joined: 29 May 2009
Posts: 31
Followers: 0

Kudos [?]: 7 [0], given: 0

GMAT Prep, question 3 [#permalink]

### Show Tags

28 Sep 2009, 22:04
Hi, I couldn't figure this out on the GMAT Prep. It's question number 3:

For all positive integers m, [m] = 3m when m is odd and [m] = (1/2)(m) when m is even. Which of the following is equivalent to [9] x [6]?

A. 81

B. 54

C. 36

D. 27

E. 18

I already know what the correct answer is so I just want to know the math that derives the correct answer. Any help would be appreciated. Thanks!
GMAT Prep, question 3   [#permalink] 28 Sep 2009, 22:04

Go to page    1   2   3   4    Next  [ 71 posts ]

Similar topics Replies Last post
Similar
Topics:
2 If m is a positive integer, and m/15 = 8.2, what is the remainder when 1 24 Apr 2016, 15:18
6 If 3^m3^m3^m = 9^n, then m/n = 6 04 Nov 2014, 10:21
39 For all positive integers m, [m]=3m when m is odd 14 08 Sep 2010, 06:38
6 For all positive integers m, [m]=3m when m is odd and [m]= 8 22 Nov 2011, 18:33
34 The function f(m) is defined for all positive integers m as 9 26 Jan 2011, 14:00
Display posts from previous: Sort by

# For all positive integers m, [m]=3m when m is odd and [m]=

 Question banks Downloads My Bookmarks Reviews Important topics

 Powered by phpBB © phpBB Group and phpBB SEO Kindly note that the GMAT® test is a registered trademark of the Graduate Management Admission Council®, and this site has neither been reviewed nor endorsed by GMAC®.