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

It is currently 25 May 2015, 15:59

Today:

Free Access to GMAT Club Tests - May 25th for Memorial Day!!


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 and [m]=

  Question banks Downloads My Bookmarks Reviews Important topics  
Author Message
TAGS:
Senior Manager
Senior Manager
avatar
Joined: 31 Aug 2009
Posts: 421
Location: Sydney, Australia
Followers: 6

Kudos [?]: 146 [0], given: 20

Re: GMAT Prep, question 3 [#permalink] New post 28 Sep 2009, 21:10
9 is odd: [9] = 3*9 = 27
6 is even: [6] = (1/2)*6 = 3

Hence [9] x [6] = 27 x 3 = 81
Ans: A
Intern
Intern
avatar
Joined: 29 May 2009
Posts: 31
Followers: 0

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

Re: GMAT Prep, question 3 [#permalink] New post 28 Sep 2009, 21:28
yangsta8 wrote:
9 is odd: [9] = 3*9 = 27
6 is even: [6] = (1/2)*6 = 3

Hence [9] x [6] = 27 x 3 = 81
Ans: A


My bad. The answers should have been worded as follows (which makes a difference).

A. [81]

B. [54]

C. [36]

D. [27]

E. [18]

When the answers are reworded, the correct answer is D, or [27]. It looks like GMAC was tricky with this question and some readers didn't notice the answers were surrounded by a box. Fortunately, I was lucky enough to find a thread that discusses this:

gmatprep-question-82890.html#p621771

Looks like I wasn't the only one that was tricked, lol.
Manager
Manager
avatar
Joined: 14 Dec 2008
Posts: 171
Followers: 1

Kudos [?]: 16 [0], given: 39

Re: GMAT Prep, question 3 [#permalink] New post 29 Sep 2009, 10:51
agree with gmattester123, good catch!. :-)
Intern
Intern
avatar
Joined: 03 Oct 2009
Posts: 2
Followers: 0

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

Quant question [#permalink] New post 07 Oct 2009, 11:37
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]?
A)[81]
B)[54]
C)[36]
D)[27]
E)[18]

can anybody answer this with explanation.

Thanks
Manager
Manager
User avatar
Joined: 01 Jan 2009
Posts: 96
Location: India
Schools: LBS
Followers: 2

Kudos [?]: 59 [0], given: 6

Re: Quant question [#permalink] New post 07 Oct 2009, 13:43
yogitapruthi 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]?
A)[81]
B)[54]
C)[36]
D)[27]
E)[18]

can anybody answer this with explanation.

Thanks



[9] = 3 x 9 = 27
[6] = 6/2 = 3

so [9].[6]= 27 x 3 = [27] (as 27 is odd)
_________________

The Legion dies, it does not surrender.

Expert Post
Founder
Founder
User avatar
Affiliations: AS - Gold, UA - Silver, HH-Diamond
Joined: 04 Dec 2002
Posts: 12771
Location: United States (WA)
GMAT 1: 750 Q49 V42
GPA: 3.5
WE: Information Technology (Hospitality and Tourism)
Followers: 2664

Kudos [?]: 12806 [0], given: 3844

GMAT ToolKit User Premium Member CAT Tests
Re: Quant question [#permalink] New post 07 Oct 2009, 20:13
Expert's post

!
Please post PS questions in the PS subforum: gmat-problem-solving-ps-140/
Please post DS questions in the DS subforum: gmat-data-sufficiency-ds-141/

No posting of PS/DS questions is allowed in the main Math forum.

_________________

Founder of GMAT Club

Just starting out with GMAT? Start here... | Want to know your GMAT Score? Try GMAT Score Estimator
Need GMAT Book Recommendations? Best GMAT Books

Co-author of the GMAT Club tests

Have a blog? Feature it on GMAT Club!

GMAT Club Premium Membership - big benefits and savings

Manager
Manager
User avatar
Joined: 18 Jul 2009
Posts: 170
Location: India
Schools: South Asian B-schools
Followers: 2

Kudos [?]: 65 [0], given: 37

Re: Quant question [#permalink] New post 08 Oct 2009, 02:17
Ans is OA D [27]
here one thing to notice is [] is a function or operator...you have to use it in your option choice

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

A) [81] = 81 x 3 = 343 :(
B) [54] = 1/2 x 54 = 27 :(
C) [36] = 1/2 x 36 = 18 :(
D) [27] = 3 x 27 = 81 :)

Hence OA D is our ans
_________________

Bhushan S.
If you like my post....Consider it for Kudos :-D

Intern
Intern
avatar
Joined: 28 Sep 2009
Posts: 37
Location: Toronto, Ontario, Canada
Followers: 0

Kudos [?]: 1 [0], given: 2

Seemingly easy PS question! Help! [#permalink] New post 29 Dec 2009, 17:57
hi guys,
I can't figure out why I can't get this question right, appreciate all comments in advance.

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

1) [81]
2) [18]
3) [27]
4) [54]
5) [36]

now my answer was 81 but the right answer according to Official GMAT is 27 and I can't seem to understand why! please help me out here.
Intern
Intern
User avatar
Joined: 23 Dec 2009
Posts: 2
Location: San Diego
Schools: San Diego State University
Followers: 0

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

Re: Seemingly easy PS question! Help! [#permalink] New post 29 Dec 2009, 19:40
Funny, I came across this questions today as well and I answered it the same way. It's not that 81 is wrong, it's that we chose the wrong answer. I think the asterisk represents a box, right? All of the answer choices were boxed, therefore we're still supposed to follow the rules mentioned in the question. 27* is right because 27 multiplied by 3 (the rule for odd integers) is 81.
Intern
Intern
avatar
Joined: 28 Sep 2009
Posts: 37
Location: Toronto, Ontario, Canada
Followers: 0

Kudos [?]: 1 [0], given: 2

Re: Seemingly easy PS question! Help! [#permalink] New post 29 Dec 2009, 19:59
The asterisk is a box! But I couldn't copy and paste so I had to come up with something :)
Oh God, now I got it. You're soo right! I completely ignored the fact that the answers were in the box too. My bad. Thanks a lot!
Did you look at my other post too? I have a feeling I'm ignoring something obvious in that one too!
Thanks again!
Intern
Intern
avatar
Joined: 29 Nov 2009
Posts: 22
Location: Toronto
Followers: 0

Kudos [?]: 6 [0], given: 5

Re: Seemingly easy PS question! Help! [#permalink] New post 11 Jan 2010, 17:24
Parisa1362 wrote:
hi guys,
I can't figure out why I can't get this question right, appreciate all comments in advance.

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

1) [81]
2) [18]
3) [27]
4) [54]
5) [36]

now my answer was 81 but the right answer according to Official GMAT is 27 and I can't seem to understand why! please help me out here.


Because [m] = 3m when m is odd, [9]=3m, m=3. Using the same logic for [6], [6]=3
3*3=9
If you put this back in [m] form you get 3*9=[27] (we must use 3m because m is odd, if it were even it would be .5*9)
Thus answer choice C

Also, you can confirm this by [27]=3m, m=9

Does that help?
Manager
Manager
avatar
Joined: 27 Apr 2008
Posts: 191
Followers: 1

Kudos [?]: 46 [0], given: 1

Re: Seemingly easy PS question! Help! [#permalink] New post 11 Jan 2010, 18:10
Another way of looking at this is as follows:
[9] x [6] = ?

[9] = 3(9) = 27
[6] = 0.5(6) = 3
Therefore, [9]x[6] = 27x3 = 81

We need a [x] that equals to 81. Only [27]=3(27)=81. Therefore the answer is C) [27].
Intern
Intern
avatar
Joined: 05 Aug 2009
Posts: 8
Followers: 0

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

Tough Algebra, Can anyone help me? Thanks!! [#permalink] New post 08 Feb 2010, 14:20
Attachment:
Presentation1.jpg
Presentation1.jpg [ 26.15 KiB | Viewed 3681 times ]



[Reveal] Spoiler:
Thanks for the help.
It's from GMAT Prep, my answer is 81, but OA is 27. Anyone knows how to get the right answer?
Thank you so much again for the great help and time!!
Expert Post
1 KUDOS received
GMAT Tutor
avatar
Joined: 24 Jun 2008
Posts: 1044
Location: Toronto
Followers: 287

Kudos [?]: 841 [1] , given: 4

Re: Tough Algebra, Can anyone help me? Thanks!! [#permalink] New post 08 Feb 2010, 14:52
1
This post received
KUDOS
Expert's post
We know that [9] = 3*9 = 27, since [x] = 3x when x is odd. We also know that [6] = 3, since [x] = x/2 when x is even. So [9]*[6] = 27*3 = 81.

Now, many people choose the wrong answer to this question, despite doing all of the work correctly, because they do not notice that the answer choices are all in boxes - a devious GMAT trap. So the answer choice which reads [81] is not equal to the number 81; it is equal to 3*81 = 243, because [x] = 3x when x is odd. The correct answer here is [27], which is equal to the number 81.
_________________

Nov 2011: After years of development, I am now making my advanced Quant books and high-level problem sets available for sale. Contact me at ianstewartgmat at gmail.com for details.

Private GMAT Tutor based in Toronto

Intern
Intern
avatar
Joined: 10 Oct 2009
Posts: 25
Followers: 0

Kudos [?]: 3 [0], given: 1

Re: Tough Algebra, Can anyone help me? Thanks!! [#permalink] New post 09 Feb 2010, 00:05
note the answers given are in box
Manager
Manager
avatar
Joined: 10 Jan 2010
Posts: 192
Location: Germany
Concentration: Strategy, General Management
Schools: IE '15 (M)
GMAT 1: Q V
GPA: 3
WE: Consulting (Telecommunications)
Followers: 2

Kudos [?]: 23 [0], given: 7

Re: Tough Algebra, Can anyone help me? Thanks!! [#permalink] New post 09 Feb 2010, 03:53
Since the numbers are in boxes, we have to solve the Question twice.

First look at the given numbers (9 is odd so 3m, 6 is even so 1/2m)
[9]x[6] = 3(9)x1/2(6) = 81

Now look at 81 which is obviously odd which means that the answer has to be 3m = 81 (answer is also in a box)

hence, m = [27]
Intern
Intern
avatar
Joined: 05 Aug 2009
Posts: 8
Followers: 0

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

Re: Tough Algebra, Can anyone help me? Thanks!! [#permalink] New post 09 Feb 2010, 21:03
Thank you sooo sooooo soooo much for helping me this. And you guys are amazing and brilliant!!! I got it now!!! :) Thank you!!!
Current Student
avatar
Joined: 20 Jun 2009
Posts: 168
Schools: Yale SOM Class of 2013
Followers: 4

Kudos [?]: 22 [0], given: 0

GMAT Prep 1: Symbolism [#permalink] New post 13 Feb 2010, 09:56
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?

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

Clear, concise explanations welcome!

[Reveal] Spoiler:
OA = D

Last edited by carriedinterest on 13 Feb 2010, 10:29, edited 2 times in total.
Manager
Manager
User avatar
Status: Getting ready for the internship summer
Joined: 07 Jun 2009
Posts: 51
Location: Rochester, NY
Schools: Simon
WE 1: JPM - Treasury
Followers: 0

Kudos [?]: 19 [0], given: 23

Re: GMAT Prep 1: Symbolism [#permalink] New post 13 Feb 2010, 10:14
You posted this question incorrectly because all of the answers need to be surrounded with a box, or in your notation, an underline. Failing to do this misses the point of the problem.
Current Student
avatar
Joined: 20 Jun 2009
Posts: 168
Schools: Yale SOM Class of 2013
Followers: 4

Kudos [?]: 22 [0], given: 0

Re: GMAT Prep 1: Symbolism [#permalink] New post 13 Feb 2010, 10:18
LJ wrote:
You posted this question incorrectly because all of the answers need to be surrounded with a box, or in your notation, an underline. Failing to do this misses the point of the problem.


Good spot. I've corrected the answer choices. You're obviously familiar with the problem - care to answer?
Re: GMAT Prep 1: Symbolism   [#permalink] 13 Feb 2010, 10:18

Go to page   Previous    1   2   3   4    Next  [ 63 posts ] 

    Similar topics Author Replies Last post
Similar
Topics:
23 Experts publish their posts in the topic For all positive integers m, [m]=3m when m is odd Guduna 14 08 Sep 2010, 05:38
3 Experts publish their posts in the topic For all positive integers m, [m]=3m when m is odd and [m]= galaxyblue 6 22 Nov 2011, 17:33
1 For all the positive integers /m/, /m/ = 3m when m is odd study 15 15 Nov 2008, 22:54
For all positive integers m, m = 3m when m is odd and m = hadi86 5 15 Jan 2008, 19:09
For all positive integers m, m*=3m when m is odd and yach 5 06 Mar 2006, 15:01
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  


GMAT Club MBA Forum Home| About| Privacy Policy| 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®.