Tough Algebra, Can anyone help me? Thanks!!

This topic has expert replies
Source: — Problem Solving |

User avatar
Legendary Member
Posts: 1132
Joined: Mon Jul 20, 2009 3:38 am
Location: India
Thanked: 64 times
Followed by:6 members
GMAT Score:760

by harsh.champ » Mon Feb 08, 2010 3:15 pm
YTT wrote: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!!
Now, box[9]= 3 x 9 = 27 (as 9 is odd)
box[6]= 6/2 =3 (as 6 is even)

So,box[9] x box[6] = 27 x 3 =81.

I hope you get it now,
Did you leave out the box[6] part??
Can you post your problem approach??

Anyways,I hope it is clear now.If u still have any doubts just submit it in the corresponding posts.:)
It takes time and effort to explain, so if my comment helped you please press Thanks button :)



Just because something is hard doesn't mean you shouldn't try,it means you should just try harder.

"Keep Walking" - Johnny Walker :P

User avatar
Master | Next Rank: 500 Posts
Posts: 109
Joined: Mon Oct 12, 2009 4:58 am
Thanked: 12 times
Followed by:1 members
GMAT Score:720

by jeffedwards » Mon Feb 08, 2010 5:16 pm
That's really interesting. I get 81 too. I wonder if the answer is just wrong. Sorry

Master | Next Rank: 500 Posts
Posts: 184
Joined: Sat Apr 14, 2007 9:23 am
Location: Madison, WI
Thanked: 17 times

by ldoolitt » Mon Feb 08, 2010 5:46 pm
I concur with the 81. I think the OA is wrong.

User avatar
Legendary Member
Posts: 1560
Joined: Tue Nov 17, 2009 2:38 am
Thanked: 137 times
Followed by:5 members

by thephoenix » Tue Feb 09, 2010 2:15 am
oa is not wrng its 27

Now, box[9]= 3 x 9 = 27 (as 9 is odd)
box[6]= 6/2 =3 (as 6 is even)

So,box[9] x box[6] = 27 x 3 =81.

till here its okay but
the ans are converted into symbol
so 81=l27l; bcoz l27l=3*27=81

hence ans is D

User avatar
Community Manager
Posts: 1537
Joined: Mon Aug 10, 2009 6:10 pm
Thanked: 653 times
Followed by:252 members

by papgust » Tue Feb 09, 2010 2:28 am
That's a great example of GMAT traps!

User avatar
Legendary Member
Posts: 1132
Joined: Mon Jul 20, 2009 3:38 am
Location: India
Thanked: 64 times
Followed by:6 members
GMAT Score:760

by harsh.champ » Tue Feb 09, 2010 3:16 am
thephoenix wrote:oa is not wrng its 27

Now, box[9]= 3 x 9 = 27 (as 9 is odd)
box[6]= 6/2 =3 (as 6 is even)

So,box[9] x box[6] = 27 x 3 =81.

till here its okay but
the ans are converted into symbol
so 81=l27l; bcoz l27l=3*27=81

hence ans is D
Thanks thephoenix for identifying the trap.
I do agree with papgust that this is one of the best examples of GMAT traps.
Suggestion:-I think this thread should be posted in a sumwat more visible page of the site to show an example of GMAT traps.
What-say people?
It takes time and effort to explain, so if my comment helped you please press Thanks button :)



Just because something is hard doesn't mean you shouldn't try,it means you should just try harder.

"Keep Walking" - Johnny Walker :P

Master | Next Rank: 500 Posts
Posts: 184
Joined: Sat Apr 14, 2007 9:23 am
Location: Madison, WI
Thanked: 17 times

by ldoolitt » Tue Feb 09, 2010 4:28 am
I agree. Thats one of the best traps that I have seen!

User avatar
Legendary Member
Posts: 758
Joined: Sat Aug 29, 2009 9:32 pm
Location: Bangalore,India
Thanked: 67 times
Followed by:2 members

by sumanr84 » Tue Feb 16, 2010 9:48 am
My goodness :)..definitely cud hav done wrong on G-Day with time pressure overhead..
I am on a break !!

Senior | Next Rank: 100 Posts
Posts: 34
Joined: Wed Nov 11, 2009 11:23 am
Thanked: 8 times
Followed by:1 members

by amittilak » Tue Feb 16, 2010 11:50 am
son of a gunn........ this is probably the best traps I have seen.. especially if you get this in questions 25 and up, when most people are running little short on time.

Junior | Next Rank: 30 Posts
Posts: 16
Joined: Fri Nov 13, 2009 7:50 am

by Lance123 » Tue Feb 16, 2010 5:50 pm
amazing trap :l

Newbie | Next Rank: 10 Posts
Posts: 8
Joined: Sun Feb 14, 2010 12:53 pm
Thanked: 1 times

by ejose » Tue Feb 16, 2010 7:14 pm
After about 10 minutes and cursing at the screen, I finally had the "you've gotta be kidding me" moment. Wow, that's a simple, yet gross problem. It's great to see these though ... god knows I'll never miss this in the event that it shows up on test day.

User avatar
Legendary Member
Posts: 1132
Joined: Mon Jul 20, 2009 3:38 am
Location: India
Thanked: 64 times
Followed by:6 members
GMAT Score:760

by harsh.champ » Thu Feb 18, 2010 4:16 am
sumanr84 wrote:My goodness :)..definitely cud hav done wrong on G-Day with time pressure overhead..
Hey ppl,
I do agree with sumanr84 that a star rating should be provided alongside the questions.
Also on the main forum page there should be an option of sorting by the question ratings.That way ,in a time crunch we would know which questions to practice and which to not.

On another note,this question will surely get a 10/10 rating according to me - an ideal example of what to expect on the D-Day.
It takes time and effort to explain, so if my comment helped you please press Thanks button :)



Just because something is hard doesn't mean you shouldn't try,it means you should just try harder.

"Keep Walking" - Johnny Walker :P