Author 
Message 
TAGS:

Hide Tags

Intern
Joined: 05 Sep 2010
Posts: 20

For all positive integers m, [m]=3m when m is odd [#permalink]
Show Tags
08 Sep 2010, 05:38
3
This post received KUDOS
37
This post was BOOKMARKED
Question Stats:
56% (00:38) correct 44% (00:32) wrong based on 1161 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]
Official Answer and Stats are available only to registered users. Register/ Login.
Last edited by Bunuel on 23 Jul 2013, 09:37, edited 2 times in total.
Edited the question.



Math Expert
Joined: 02 Sep 2009
Posts: 43380

Re: Very easy but still got wrong.. Need Your answer [#permalink]
Show Tags
08 Sep 2010, 06:41
20
This post received KUDOS
Expert's post
34
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: whenxisevenx21whenxisodd2x1then132059.html
_________________
New to the Math Forum? Please read this: Ultimate GMAT Quantitative Megathread  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? Extrahard Quant Tests with Brilliant Analytics



Intern
Joined: 05 Sep 2010
Posts: 20

Re: Very easy but still got wrong.. Need Your answer [#permalink]
Show Tags
08 Sep 2010, 07:01
1
This post received KUDOS
Bunuel
Thank you so much I didn't look at the answers that they were also in squares..
Thanks



Manager
Joined: 13 Jul 2010
Posts: 159

Re: Very easy but still got wrong.. Need Your answer [#permalink]
Show Tags
08 Dec 2010, 19:36
got answer D is explained above. Bunuel good point on the even number bracket as well for the function. Did not think of that.



Intern
Joined: 13 Jul 2010
Posts: 9

Re: Special Characters [#permalink]
Show Tags
22 Nov 2011, 21:12
galaxyblue wrote: [m] = 3m when m is odd [m] = 1/2m when m is even what is [9]x[6]?
A 81 B 54 C 36 D 27 E 18 9 is odd, 6 is even. By the way this is set up, it should be 3*9*(1/2*6) with that said, 27*3 should be A IMO



Intern
Joined: 10 Oct 2011
Posts: 32
Concentration: Operations, Marketing
GPA: 3.1
WE: Project Management (NonProfit and Government)

Re: Special Characters [#permalink]
Show Tags
23 Nov 2011, 05:46
rooster wrote: 9 is odd, 6 is even.
By the way this is set up, it should be 3*9*(1/2*6)
with that said, 27*3 should be A IMO
That is what I got, but it is not the answer. I even set it up like: 9 = 3m, therefore m is 3 and 6 = 1/2 m, then m = 12. So 12 x 3 = 36. Still wrong. So then I did 9x6 = [54] = 3m x 1/2m => 54 = 3/2m => solve for m, m=36
_________________
Kelly
Give Me Kudos if you like my post!



Senior Manager
Joined: 30 Aug 2009
Posts: 281
Location: India
Concentration: General Management

Re: Formula Question  Gmatprep [#permalink]
Show Tags
10 Jan 2012, 06:59
2
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
Joined: 19 Aug 2011
Posts: 27
Concentration: Finance, Entrepreneurship

Re: For all positive integers m, [m]=3m when m is odd [#permalink]
Show Tags
03 Apr 2012, 01:41
2
This post received KUDOS
Pure deception. Got caught in the trap.



Manager
Status: I will not stop until i realise my goal which is my dream too
Joined: 25 Feb 2010
Posts: 221

Re: Very easy but still got wrong.. Need Your answer [#permalink]
Show Tags
03 Apr 2012, 05:53
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



Intern
Joined: 04 Apr 2012
Posts: 2
Location: India

Re: Special Characters [#permalink]
Show Tags
07 Apr 2012, 08:23
galaxyblue wrote: rooster wrote: 9 is odd, 6 is even.
By the way this is set up, it should be 3*9*(1/2*6)
with that said, 27*3 should be A IMO
That is what I got, but it is not the answer. I even set it up like: 9 = 3m, therefore m is 3 and 6 = 1/2 m, then m = 12. So 12 x 3 = 36. Still wrong. So then I did 9x6 = [54] = 3m x 1/2m => 54 = 3/2m => solve for m, m=36 Going by the answer, they might have calculated this way [9][6] = [54] = 54/2 =27, but I would still go for option A.



Math Expert
Joined: 02 Sep 2009
Posts: 43380

Re: For all positive integers m, [m]=3m when m is odd [#permalink]
Show Tags
21 Jun 2013, 02:47



Intern
Joined: 10 Apr 2014
Posts: 33

Re: PS question help.... [#permalink]
Show Tags
13 Apr 2014, 01:32
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. 54c. 36d. 27e. 18The answer would be D because 27= 3*27 = 81  Kudos if the post helped



Senior Manager
Joined: 15 Aug 2013
Posts: 295

Re: Very easy but still got wrong.. Need Your answer [#permalink]
Show Tags
13 Jun 2014, 18:13
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: whenxisevenx21whenxisodd2x1then132059.htmlHi 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



Math Expert
Joined: 02 Sep 2009
Posts: 43380

Re: Very easy but still got wrong.. Need Your answer [#permalink]
Show Tags
14 Jun 2014, 00:50
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: whenxisevenx21whenxisodd2x1then132059.htmlHi 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: Ultimate GMAT Quantitative Megathread  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? Extrahard Quant Tests with Brilliant Analytics



SVP
Status: The Best Or Nothing
Joined: 27 Dec 2012
Posts: 1842
Location: India
Concentration: General Management, Technology
WE: Information Technology (Computer Software)

Re: For all positive integers m, [m]=3m when m is odd and [m]= [#permalink]
Show Tags
19 Jun 2014, 03:51
1
This post received KUDOS
1
This post was BOOKMARKED
[9] = 9 * 3 = 27 \([6] = \frac{6}{2} = 3\) [9] * [6] = 27 * 3 = 81 ............. (1)From all the given options, we require to calculate to get answer 81 A. [81] = 81 * 3 = 243 .... IGNORE \(B. [54] = \frac{54}{2} = 27 ......... IGNORE\) C. [37] = 37 * 3 = 111 ..... IGNORE D. [27] = 27 * 3 = 81 ........... Matches with (1)\(E. [18] = \frac{18}{2} = 9 ........... IGNORE\) Answer = D
_________________
Kindly press "+1 Kudos" to appreciate



Intern
Joined: 12 Aug 2014
Posts: 7
Location: Peru
GPA: 3.82

Re: For all positive integers m, [m]=3m when m is odd [#permalink]
Show Tags
10 Dec 2014, 11:35
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: whenxisevenx21whenxisodd2x1then132059.htmlEasy math but very tricky. Excelent explanation by Bunuel.



LBS Thread Master
Joined: 13 Jan 2015
Posts: 112
Location: United Kingdom
Concentration: Other, General Management

Re: For all positive integers m, [m]=3m when m is odd [#permalink]
Show Tags
24 Mar 2015, 04:11
Dang, I crosschecked 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



Retired Moderator
Joined: 12 Aug 2015
Posts: 2345
GRE 1: 323 Q169 V154

Re: For all positive integers m, [m]=3m when m is odd and [m]= [#permalink]
Show Tags
22 Apr 2016, 16:28
Excellent Question...!! Here is my approach Here [9] = 27 [6]=3 => multiplying them we get 81 = 27*3 so [27] SMASH that D
_________________
Give me a hell yeah ...!!!!!



Manager
Joined: 16 Jul 2015
Posts: 50
GMAT 1: 580 Q37 V33 GMAT 2: 580 Q39 V31 GMAT 3: 560 Q40 V28 GMAT 4: 580 Q37 V32 GMAT 5: 680 Q45 V37 GMAT 6: 690 Q47 V37

Re: For all positive integers m, [m]=3m when m is odd [#permalink]
Show Tags
14 Jul 2016, 06:29
I have tried to understand this but not sure if I have got it correct.Pls guide me if I am wrong.So [m]=3m when m is odd ,therefore[9]=3*9 =27 and [6]=1/2*6=3 as m is even ;27*3=81 but answer choices are showing us[] so basically we have to pick an answer choice where the[]=81.Two ways we can get[81] is 3*27 and 1/2*162=[81] .Since we do not have answer option 162,so we go with [27]. But still again in the highlighted parts it is not inside the box[]



Target Test Prep Representative
Status: Founder & CEO
Affiliations: Target Test Prep
Joined: 14 Oct 2015
Posts: 2069
Location: United States (CA)

Re: For all positive integers m, [m]=3m when m is odd [#permalink]
Show Tags
16 Jan 2017, 17:04
Guduna wrote: 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] We are given that [m] = 3m when m is odd, and [m] = (1/2)*m when m is even, and we must determine the value of [9]*[6]. Since 9 is odd, [9] = 3 x 9 = 27. Since 6 is even, [6] = (1/2) x 6 = 3. Thus, [9]*[6] = 27 x 3 = 81. Now we must determine which “bracketed” answer choice is equal to 81. Since 27 is odd, we see that [27] = 27 x 3 = 81. Answer: D
_________________
Scott WoodburyStewart
Founder and CEO
GMAT Quant SelfStudy Course
500+ lessons 3000+ practice problems 800+ HD solutions




Re: For all positive integers m, [m]=3m when m is odd
[#permalink]
16 Jan 2017, 17:04



Go to page
1 2
Next
[ 21 posts ]



