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

It is currently 27 Jun 2016, 07:57
GMAT Club Tests

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.

Events & Promotions

Events & Promotions in June
Open Detailed Calendar

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

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

Hide Tags

1 KUDOS received
Intern
Intern
avatar
Joined: 05 Sep 2010
Posts: 20
Followers: 0

Kudos [?]: 13 [1] , given: 80

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

Show Tags

New post 08 Sep 2010, 06:38
1
This post received
KUDOS
11
This post was
BOOKMARKED
00:00
A
B
C
D
E

Difficulty:

  35% (medium)

Question Stats:

59% (01:36) correct 41% (00:34) wrong based on 465 sessions

HideShow timer Statistics

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

A. [81]
B. [54]
C. [37]
D. [27]
E. [18]
[Reveal] Spoiler: OA

Last edited by Bunuel on 23 Jul 2013, 10:37, edited 2 times in total.
Edited the question.
Expert Post
10 KUDOS received
Math Expert
User avatar
Joined: 02 Sep 2009
Posts: 33525
Followers: 5937

Kudos [?]: 73609 [10] , given: 9903

Re: Very easy but still got wrong.. Need Your answer [#permalink]

Show Tags

New post 08 Sep 2010, 07:41
10
This post received
KUDOS
Expert's post
19
This post was
BOOKMARKED
Guduna wrote:
For all positive integers m, m*= 3m when m is odd and m*=1/2 when m is even. Which of the following is equivalent to 9* x 6*
81
54
36
27
18


Pleas post the questions in their original form.

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

A. [81]
B. [54]
C. [37]
D. [27]
E. [18]

Notice that [] is just some function such that "[m]=3m when m is odd and [m]=(1/2)*m when m is even".

So, [m]=3m when m is odd, [m]=(1/2)*m when m is even.
As 9 is odd then [9] equals to 3*9=27;
As 6 is even then [6] equals to 1/2*6=3;

So [9]*[6]=27*3=81. Note that numbers in the answer choices are also in boxes, so we have: [m]=81. m could be 27 (in this case as 27 is odd [27]=3*27=81) OR 162 (in this case as 162 is even [162]=162/2=81) --> only [27] is in the answer choices.

Answer: D.

Similar question to practice: when-x-is-even-x-2-1-when-x-is-odd-2x-1-then-132059.html
_________________

New to the Math Forum?
Please read this: All You Need for Quant | PLEASE READ AND FOLLOW: 12 Rules for Posting!!!

Resources:
GMAT Math Book | Triangles | Polygons | Coordinate Geometry | Factorials | Circles | Number Theory | Remainders; 8. Overlapping Sets | PDF of Math Book; 10. Remainders | GMAT Prep Software Analysis | SEVEN SAMURAI OF 2012 (BEST DISCUSSIONS) | Tricky questions from previous years.

Collection of Questions:
PS: 1. Tough and Tricky questions; 2. Hard questions; 3. Hard questions part 2; 4. Standard deviation; 5. Tough Problem Solving Questions With Solutions; 6. Probability and Combinations Questions With Solutions; 7 Tough and tricky exponents and roots questions; 8 12 Easy Pieces (or not?); 9 Bakers' Dozen; 10 Algebra set. ,11 Mixed Questions, 12 Fresh Meat

DS: 1. DS tough questions; 2. DS tough questions part 2; 3. DS tough questions part 3; 4. DS Standard deviation; 5. Inequalities; 6. 700+ GMAT Data Sufficiency Questions With Explanations; 7 Tough and tricky exponents and roots questions; 8 The Discreet Charm of the DS; 9 Devil's Dozen!!!; 10 Number Properties set., 11 New DS set.


What are GMAT Club Tests?
Extra-hard Quant Tests with Brilliant Analytics

Intern
Intern
avatar
Joined: 05 Sep 2010
Posts: 20
Followers: 0

Kudos [?]: 13 [0], given: 80

Re: Very easy but still got wrong.. Need Your answer [#permalink]

Show Tags

New post 08 Sep 2010, 08:01
Bunuel

Thank you so much I didn't look at the answers that they were also in squares..

Thanks
Manager
Manager
User avatar
Joined: 13 Jul 2010
Posts: 169
Followers: 1

Kudos [?]: 51 [0], given: 7

Re: Very easy but still got wrong.. Need Your answer [#permalink]

Show Tags

New post 08 Dec 2010, 20:36
got answer D is explained above. Bunuel good point on the even number bracket as well for the function. Did not think of that.
1 KUDOS received
Senior Manager
Senior Manager
avatar
Joined: 30 Aug 2009
Posts: 286
Location: India
Concentration: General Management
Followers: 3

Kudos [?]: 138 [1] , given: 5

Re: Formula Question - Gmatprep [#permalink]

Show Tags

New post 10 Jan 2012, 07:59
1
This post received
KUDOS
1
This post was
BOOKMARKED
Janealams wrote:
I have exam tomorrow. I will really appreciate if any of you can explain solution to this question. Thanks :)

Why should we not solve 9 and 6 individually?


when m is 9 (odd) then [m] = 3 * m = [9] = 27 and

m is 6 (even) then [m] =1/2m = [6] = (1/2)*6 = 3

so we get [9] * [6] = 27 *3 = 81

but answers are all in [] so 81 (odd and hence in 3m format) will be equal to [27]

[] used for box symbol used in q
Intern
Intern
avatar
Joined: 19 Aug 2011
Posts: 29
Concentration: Finance, Entrepreneurship
Followers: 0

Kudos [?]: 10 [0], given: 2

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

Show Tags

New post 03 Apr 2012, 02:41
Pure deception. Got caught in the trap. :shock:
Manager
Manager
avatar
Status: I will not stop until i realise my goal which is my dream too
Joined: 25 Feb 2010
Posts: 235
Schools: Johnson '15
Followers: 2

Kudos [?]: 48 [0], given: 16

Re: Very easy but still got wrong.. Need Your answer [#permalink]

Show Tags

New post 03 Apr 2012, 06:53
Bunuel wrote:
Guduna wrote:
For all positive integers m, m*= 3m when m is odd and m*=1/2 when m is even. Which of the following is equivalent to 9* x 6*
81
54
36
27
18


Pleas post the questions in their original form.

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

A. [81]
B. [54]
C. [37]
D. [27]
E. [18]

Note that [] is just some function such that "[m]=3m when m is odd and [m]=(1/2)*m when m is even".

So, [m]=3m when m is odd, [m]=(1/2)*m when m is even.
As 9 is odd then [9] equals to 3*9=27;
As 6 is even then [6] equals to 1/2*6=3;

So [9]*[6]=27*3=81. Note that numbers in the answer choices are also in boxes, so we have: [m]=81. m could be 27 (in this case as 27 is odd [27]=3*27=81) OR 162 (in this case as 162 is even [162]=162/2=81) --> only [27] is in the answer choices.

Answer: D.



i had selected A, but then realised my mistake....Buneal the god....wounderful explanation....
_________________

Regards,
Harsha

Note: Give me kudos if my approach is right , else help me understand where i am missing.. I want to bell the GMAT Cat ;)

Satyameva Jayate - Truth alone triumphs

Expert Post
Math Expert
User avatar
Joined: 02 Sep 2009
Posts: 33525
Followers: 5937

Kudos [?]: 73609 [0], given: 9903

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

Show Tags

New post 21 Jun 2013, 03:47
Expert's post
Bumping for review and further discussion*. Get a kudos point for an alternative solution!

*New project from GMAT Club!!! Check HERE

All DS Functions and Custom Characters questions: search.php?search_id=tag&tag_id=40
All PS Functions and Custom Characters questions: search.php?search_id=tag&tag_id=61

_________________

New to the Math Forum?
Please read this: All You Need for Quant | PLEASE READ AND FOLLOW: 12 Rules for Posting!!!

Resources:
GMAT Math Book | Triangles | Polygons | Coordinate Geometry | Factorials | Circles | Number Theory | Remainders; 8. Overlapping Sets | PDF of Math Book; 10. Remainders | GMAT Prep Software Analysis | SEVEN SAMURAI OF 2012 (BEST DISCUSSIONS) | Tricky questions from previous years.

Collection of Questions:
PS: 1. Tough and Tricky questions; 2. Hard questions; 3. Hard questions part 2; 4. Standard deviation; 5. Tough Problem Solving Questions With Solutions; 6. Probability and Combinations Questions With Solutions; 7 Tough and tricky exponents and roots questions; 8 12 Easy Pieces (or not?); 9 Bakers' Dozen; 10 Algebra set. ,11 Mixed Questions, 12 Fresh Meat

DS: 1. DS tough questions; 2. DS tough questions part 2; 3. DS tough questions part 3; 4. DS Standard deviation; 5. Inequalities; 6. 700+ GMAT Data Sufficiency Questions With Explanations; 7 Tough and tricky exponents and roots questions; 8 The Discreet Charm of the DS; 9 Devil's Dozen!!!; 10 Number Properties set., 11 New DS set.


What are GMAT Club Tests?
Extra-hard Quant Tests with Brilliant Analytics

Intern
Intern
avatar
Joined: 20 Aug 2013
Posts: 4
Schools: Rotman '16 (I)
Followers: 0

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

Reviews Badge
PS question help.... [#permalink]

Show Tags

New post 12 Apr 2014, 20:34
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 x 6

a.81
b.54
c.36
d.27
e.18

Thanks in advance
Intern
Intern
avatar
Joined: 10 Apr 2014
Posts: 33
Followers: 0

Kudos [?]: 20 [0], given: 3

Re: PS question help.... [#permalink]

Show Tags

New post 13 Apr 2014, 02:32
AJ21 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 x 6

a.81
b.54
c.36
d.27
e.18

Thanks in advance


Hi,

9 x 6 = 3*9*6/2 = 27*3 = 81

So, from the given options the answer is A.

But as the official answer you have given is D, The options should have _ line under them.
If options are:

a.81
b.54
c.36
d.27
e.18

The answer would be D because 27= 3*27 = 81


------------------------------------
Kudos if the post helped :)
Expert Post
Math Expert
User avatar
Joined: 02 Sep 2009
Posts: 33525
Followers: 5937

Kudos [?]: 73609 [0], given: 9903

Re: PS question help.... [#permalink]

Show Tags

New post 13 Apr 2014, 06:19
Expert's post
AJ21 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 x 6

a.81
b.54
c.36
d.27
e.18

Thanks in advance


Merging similar topics. Please refer to the discussion above.

P.S. Please read carefully and follow: rules-for-posting-please-read-this-before-posting-133935.html Pay attention to rules 3 and 5. Thank you.
_________________

New to the Math Forum?
Please read this: All You Need for Quant | PLEASE READ AND FOLLOW: 12 Rules for Posting!!!

Resources:
GMAT Math Book | Triangles | Polygons | Coordinate Geometry | Factorials | Circles | Number Theory | Remainders; 8. Overlapping Sets | PDF of Math Book; 10. Remainders | GMAT Prep Software Analysis | SEVEN SAMURAI OF 2012 (BEST DISCUSSIONS) | Tricky questions from previous years.

Collection of Questions:
PS: 1. Tough and Tricky questions; 2. Hard questions; 3. Hard questions part 2; 4. Standard deviation; 5. Tough Problem Solving Questions With Solutions; 6. Probability and Combinations Questions With Solutions; 7 Tough and tricky exponents and roots questions; 8 12 Easy Pieces (or not?); 9 Bakers' Dozen; 10 Algebra set. ,11 Mixed Questions, 12 Fresh Meat

DS: 1. DS tough questions; 2. DS tough questions part 2; 3. DS tough questions part 3; 4. DS Standard deviation; 5. Inequalities; 6. 700+ GMAT Data Sufficiency Questions With Explanations; 7 Tough and tricky exponents and roots questions; 8 The Discreet Charm of the DS; 9 Devil's Dozen!!!; 10 Number Properties set., 11 New DS set.


What are GMAT Club Tests?
Extra-hard Quant Tests with Brilliant Analytics

Senior Manager
Senior Manager
avatar
Joined: 15 Aug 2013
Posts: 328
Followers: 0

Kudos [?]: 38 [0], given: 23

Re: Very easy but still got wrong.. Need Your answer [#permalink]

Show Tags

New post 13 Jun 2014, 19:13
Bunuel wrote:
Guduna wrote:
For all positive integers m, m*= 3m when m is odd and m*=1/2 when m is even. Which of the following is equivalent to 9* x 6*
81
54
36
27
18


Pleas post the questions in their original form.

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

A. [81]
B. [54]
C. [37]
D. [27]
E. [18]

Notice that [] is just some function such that "[m]=3m when m is odd and [m]=(1/2)*m when m is even".

So, [m]=3m when m is odd, [m]=(1/2)*m when m is even.
As 9 is odd then [9] equals to 3*9=27;
As 6 is even then [6] equals to 1/2*6=3;

So [9]*[6]=27*3=81. Note that numbers in the answer choices are also in boxes, so we have: [m]=81. m could be 27 (in this case as 27 is odd [27]=3*27=81) OR 162 (in this case as 162 is even [162]=162/2=81) --> only [27] is in the answer choices.

Answer: D.

Similar question to practice: when-x-is-even-x-2-1-when-x-is-odd-2x-1-then-132059.html


Hi Bunuel,

I'm a little confused by this question as a whole. I can easily follow your steps but the way I did/interpreted the problem is as follows:

[9] X [6] =>

[9]=3m
m=3

[6]=1/2m
m=12

Therefore: 12*3 = 36 since since both of the [m] functions were multiplied, the answer is also in a [36] (function form). Why is that wrong?

Thanks
Expert Post
Math Expert
User avatar
Joined: 02 Sep 2009
Posts: 33525
Followers: 5937

Kudos [?]: 73609 [0], given: 9903

Re: Very easy but still got wrong.. Need Your answer [#permalink]

Show Tags

New post 14 Jun 2014, 01:50
Expert's post
russ9 wrote:
Bunuel wrote:
Guduna wrote:
For all positive integers m, m*= 3m when m is odd and m*=1/2 when m is even. Which of the following is equivalent to 9* x 6*
81
54
36
27
18


Pleas post the questions in their original form.

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

A. [81]
B. [54]
C. [37]
D. [27]
E. [18]

Notice that [] is just some function such that "[m]=3m when m is odd and [m]=(1/2)*m when m is even".

So, [m]=3m when m is odd, [m]=(1/2)*m when m is even.
As 9 is odd then [9] equals to 3*9=27;
As 6 is even then [6] equals to 1/2*6=3;

So [9]*[6]=27*3=81. Note that numbers in the answer choices are also in boxes, so we have: [m]=81. m could be 27 (in this case as 27 is odd [27]=3*27=81) OR 162 (in this case as 162 is even [162]=162/2=81) --> only [27] is in the answer choices.

Answer: D.

Similar question to practice: when-x-is-even-x-2-1-when-x-is-odd-2x-1-then-132059.html


Hi Bunuel,

I'm a little confused by this question as a whole. I can easily follow your steps but the way I did/interpreted the problem is as follows:

[9] X [6] =>

[9]=3m
m=3

[6]=1/2m
m=12

Therefore: 12*3 = 36 since since both of the [m] functions were multiplied, the answer is also in a [36] (function form). Why is that wrong?

Thanks


[9] doe not equal to 3m.
[m] = 3m when m is odd. 9 is odd , hence [9] = 3*9 = 27.

The same way, [6] does not equal to 1/2*m.
[m]=(1/2)*m when m is even. 6 is even, hence [6] = 1/2*6 = 3.

Hope it's clear.
_________________

New to the Math Forum?
Please read this: All You Need for Quant | PLEASE READ AND FOLLOW: 12 Rules for Posting!!!

Resources:
GMAT Math Book | Triangles | Polygons | Coordinate Geometry | Factorials | Circles | Number Theory | Remainders; 8. Overlapping Sets | PDF of Math Book; 10. Remainders | GMAT Prep Software Analysis | SEVEN SAMURAI OF 2012 (BEST DISCUSSIONS) | Tricky questions from previous years.

Collection of Questions:
PS: 1. Tough and Tricky questions; 2. Hard questions; 3. Hard questions part 2; 4. Standard deviation; 5. Tough Problem Solving Questions With Solutions; 6. Probability and Combinations Questions With Solutions; 7 Tough and tricky exponents and roots questions; 8 12 Easy Pieces (or not?); 9 Bakers' Dozen; 10 Algebra set. ,11 Mixed Questions, 12 Fresh Meat

DS: 1. DS tough questions; 2. DS tough questions part 2; 3. DS tough questions part 3; 4. DS Standard deviation; 5. Inequalities; 6. 700+ GMAT Data Sufficiency Questions With Explanations; 7 Tough and tricky exponents and roots questions; 8 The Discreet Charm of the DS; 9 Devil's Dozen!!!; 10 Number Properties set., 11 New DS set.


What are GMAT Club Tests?
Extra-hard Quant Tests with Brilliant Analytics

Intern
Intern
User avatar
Joined: 12 Aug 2014
Posts: 7
Location: Peru
GPA: 3.82
Followers: 0

Kudos [?]: 9 [0], given: 9

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

Show Tags

New post 10 Dec 2014, 12:35
Bunuel wrote:
Guduna wrote:
For all positive integers m, m*= 3m when m is odd and m*=1/2 when m is even. Which of the following is equivalent to 9* x 6*
81
54
36
27
18


Pleas post the questions in their original form.

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

A. [81]
B. [54]
C. [37]
D. [27]
E. [18]

Notice that [] is just some function such that "[m]=3m when m is odd and [m]=(1/2)*m when m is even".

So, [m]=3m when m is odd, [m]=(1/2)*m when m is even.
As 9 is odd then [9] equals to 3*9=27;
As 6 is even then [6] equals to 1/2*6=3;

So [9]*[6]=27*3=81. Note that numbers in the answer choices are also in boxes, so we have: [m]=81. m could be 27 (in this case as 27 is odd [27]=3*27=81) OR 162 (in this case as 162 is even [162]=162/2=81) --> only [27] is in the answer choices.

Answer: D.

Similar question to practice: when-x-is-even-x-2-1-when-x-is-odd-2x-1-then-132059.html





Easy math but very tricky. Excelent explanation by Bunuel.
Manager
Manager
avatar
Joined: 13 Jan 2015
Posts: 66
Concentration: Other, General Management
Schools: INSEAD Jan '17
Followers: 0

Kudos [?]: 12 [0], given: 45

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

Show Tags

New post 24 Mar 2015, 05:11
Dang, I cross-checked this answer and I was thinking, the GMAT would surely test harder questions on this exam and as it was the second question, it would not be this easy..

Well, I got stung, lesson learned, pay as much attention to answer choices as to the question itself...
the dam box
GMAT Club Legend
GMAT Club Legend
User avatar
Joined: 09 Sep 2013
Posts: 10203
Followers: 481

Kudos [?]: 124 [0], given: 0

Premium Member
Re: For all positive integers m, [m]=3m when m is odd [#permalink]

Show Tags

New post 10 May 2016, 02:46
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 Books | GMAT Club Tests | Best Prices on GMAT Courses | GMAT Mobile App | Math Resources | Verbal Resources

Re: For all positive integers m, [m]=3m when m is odd   [#permalink] 10 May 2016, 02:46
    Similar topics Author Replies Last post
Similar
Topics:
Experts publish their posts in the topic If m is an integer, is m odd? ShashankDave 1 03 May 2016, 23:18
Experts publish their posts in the topic The variables m and n are positive integers. When m is divided by 18, Bunuel 2 28 Apr 2016, 01:15
5 Experts publish their posts in the topic If m is a positive integer, and m/15 = 8.2, what is the remainder when stonecold 1 24 Apr 2016, 15:18
6 Experts publish their posts in the topic If 3^m3^m3^m = 9^n, then m/n = Bunuel 6 04 Nov 2014, 10:21
7 Experts publish their posts in the topic For all positive integers m, [m]=3m when m is odd and [m]= galaxyblue 8 22 Nov 2011, 18:33
Display posts from previous: Sort by

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

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


GMAT Club MBA Forum Home| About| Terms and Conditions| GMAT Club Rules| Contact| Sitemap

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®.