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

It is currently 27 Nov 2014, 23:04

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

In a sequence of 12 numbers, each term, except for the first

  Question banks Downloads My Bookmarks Reviews Important topics  
Author Message
TAGS:
Manager
Manager
avatar
Joined: 10 Sep 2012
Posts: 151
Followers: 2

Kudos [?]: 38 [0], given: 17

In a sequence of 12 numbers, each term, except for the first [#permalink] New post 03 Nov 2012, 18:36
1
This post was
BOOKMARKED
00:00
A
B
C
D
E

Difficulty:

  35% (medium)

Question Stats:

65% (02:22) correct 35% (01:34) wrong based on 141 sessions
In a sequence of 12 numbers, each term, except for the first one, is 12^11 less than the previous term. If the greatest term in the sequence is 12^12, what is the smallest term in the sequence?

A. −12^11
B. 0
C. 12^11
D. 11·12^11
E. 12^12

[Reveal] Spoiler:
Remember the formula for an arithmetic sequence: An = A1+(n-1)d

Thus, A12 = A1+(12-1)d

Where d is the difference between each pairs of consecutive terms. Since each term is 1211 less than the previous term, d=-1211Click individual answer choices for specific explanations.


From what I undersltand the formula for an arithmetic sequence represents

"some-number-in-the-sequence" = first-number-in-sequence + (the-place-of-that-number - 1) x the-difference-of-each-#-in-the-sequence

I'm not exactly sure how that formula fits into the question, could someone help me to understand?
[Reveal] Spoiler: OA
3 KUDOS received
Current Student
User avatar
Status: Done with formalities.. and back..
Joined: 15 Sep 2012
Posts: 648
Location: India
Concentration: Strategy, General Management
Schools: Olin - Wash U - Class of 2015
WE: Information Technology (Computer Software)
Followers: 37

Kudos [?]: 380 [3] , given: 23

GMAT ToolKit User Premium Member CAT Tests
Re: In a sequence of 12 numbers, each term, except for the first [#permalink] New post 03 Nov 2012, 21:24
3
This post received
KUDOS
anon1 wrote:
In a sequence of 12 numbers, each term, except for the first one, is 12^11 less than the previous term. If the greatest term in the sequence is 12^12, what is the smallest term in the sequence?

−12^11
0
12^11
11·12^11
12^12


In this question,
there are total 12 terms. and "greatest" term is 12^12. Each term is 12^11 less than previous one. What does this signify? This shows it is an AP - a decreasing one. (Notice "Each term is 12^11 less than previous one')

Therefore, 12^12 is the first term of the AP and -12^11 is the difference between successive terms, the smallest term should be the last one.

Last term = First term + (n-1)*d
therefore, Last term = 12^12 + 11*(-12^11)
=> Last term = 12^12 - 11*12^11
=> Last term = 12^11 (12-11) = 12^11
Which is the smallest term.

Hence Ans C it is.
_________________

Lets Kudos!!! ;-)
Black Friday Debrief

Manager
Manager
avatar
Joined: 10 Sep 2012
Posts: 151
Followers: 2

Kudos [?]: 38 [0], given: 17

Re: In a sequence of 12 numbers, each term, except for the first [#permalink] New post 04 Nov 2012, 10:22
Ohhhhh, I see.


I didn't realize that APs could decreasing...

I looked at the question as if 12^12 was the last number in the sequence and that the first (the smallest) was unknown. Thank you as always VIPS
2 KUDOS received
Current Student
User avatar
Status: Done with formalities.. and back..
Joined: 15 Sep 2012
Posts: 648
Location: India
Concentration: Strategy, General Management
Schools: Olin - Wash U - Class of 2015
WE: Information Technology (Computer Software)
Followers: 37

Kudos [?]: 380 [2] , given: 23

GMAT ToolKit User Premium Member CAT Tests
Re: In a sequence of 12 numbers, each term, except for the first [#permalink] New post 04 Nov 2012, 17:10
2
This post received
KUDOS
anon1 wrote:
Ohhhhh, I see.


I didn't realize that APs could decreasing...

I looked at the question as if 12^12 was the last number in the sequence and that the first (the smallest) was unknown. Thank you as always VIPS

You are welcome :)
Ps: use kudos instead ;)
_________________

Lets Kudos!!! ;-)
Black Friday Debrief

Manager
Manager
avatar
Joined: 25 Jun 2012
Posts: 71
Location: India
WE: General Management (Energy and Utilities)
Followers: 2

Kudos [?]: 44 [0], given: 15

Re: In a sequence of 12 numbers, each term, except for the first [#permalink] New post 05 Nov 2012, 03:38
hi, I am not able to understand one basic...

How can we infer that 12^12 is the first term or the last term in the sequence given in question?? Is it trial and error...???

Thanks in advance..
Current Student
User avatar
Status: Done with formalities.. and back..
Joined: 15 Sep 2012
Posts: 648
Location: India
Concentration: Strategy, General Management
Schools: Olin - Wash U - Class of 2015
WE: Information Technology (Computer Software)
Followers: 37

Kudos [?]: 380 [0], given: 23

GMAT ToolKit User Premium Member CAT Tests
Re: In a sequence of 12 numbers, each term, except for the first [#permalink] New post 05 Nov 2012, 04:00
bhavinshah5685 wrote:
hi, I am not able to understand one basic...

How can we infer that 12^12 is the first term or the last term in the sequence given in question?? Is it trial and error...???

Thanks in advance..

Question says:

1)each term, except for the first one, is 12^11 less than the previous term
=> decreasing AP
2)greatest term in the sequence is 12^12
Which term is greatest in a decreasing AP? First one!

Hope it is clear.
_________________

Lets Kudos!!! ;-)
Black Friday Debrief

Manager
Manager
avatar
Joined: 05 Nov 2012
Posts: 164
Followers: 1

Kudos [?]: 10 [0], given: 56

Re: In a sequence of 12 numbers, each term, except for the first [#permalink] New post 05 Nov 2012, 15:19
I am confused.... "except for the first one," what does this phrase in the question has to say..... remaining sequence is fine... but they never mentioned this series to be a AP series.... what if first term is 12^9? this will be the lowest term right?
Manager
Manager
avatar
Joined: 10 Sep 2012
Posts: 151
Followers: 2

Kudos [?]: 38 [0], given: 17

Re: In a sequence of 12 numbers, each term, except for the first [#permalink] New post 05 Nov 2012, 15:55
In a sequence of 12 numbers, each term, except for the first one, is 12^11 less than the previous term. If the greatest term in the sequence is 12^12, what is the smallest term in the sequence?

_ _ _ _ _ _ _ _ _ _ _ _
1 2 3 4 5 6 7 8 9 10 11 12

The above are the 12 numbers represented by underscores, and the numbers beneath represent their position in the sequence.

The question only mentions "except for the first one" because it wants to state again that there is nothing before the first number. It is a little redundant but the question wants to make itself clear.

The first number can't be 12^9 because it tells you that the numbers get smaller and 12^12 is the biggest number. Therefore 12^12 is the first number.
Moderator
Moderator
User avatar
Joined: 02 Jul 2012
Posts: 1227
Location: India
Concentration: Strategy
GMAT 1: 740 Q49 V42
GPA: 3.8
WE: Engineering (Energy and Utilities)
Followers: 70

Kudos [?]: 745 [0], given: 116

Premium Member
Re: In a sequence of 12 numbers, each term, except for the first [#permalink] New post 05 Nov 2012, 23:33
anon1 wrote:
Ohhhhh, I see.


I didn't realize that APs could decreasing...

I looked at the question as if 12^12 was the last number in the sequence and that the first (the smallest) was unknown. Thank you as always VIPS


Just a heads up... Although an A.P could be a decreasing one, the one in the question is not. The last term is 12^12 and every term before its is lesser than 12^12. So the first term is 12^11 and last term is 12^12. So the A.P is in fact an increasing one. :)

Kudos Please... If my post helped.
_________________

Did you find this post helpful?... Please let me know through the Kudos button.

Thanks To The Almighty - My GMAT Debrief

GMAT Reading Comprehension: 7 Most Common Passage Types

Current Student
User avatar
Status: Done with formalities.. and back..
Joined: 15 Sep 2012
Posts: 648
Location: India
Concentration: Strategy, General Management
Schools: Olin - Wash U - Class of 2015
WE: Information Technology (Computer Software)
Followers: 37

Kudos [?]: 380 [0], given: 23

GMAT ToolKit User Premium Member CAT Tests
Re: In a sequence of 12 numbers, each term, except for the first [#permalink] New post 06 Nov 2012, 00:12
MacFauz wrote:
Just a heads up... Although an A.P could be a decreasing one, the one in the question is not. The last term is 12^12 and every term before its is lesser than 12^12. So the first term is 12^11 and last term is 12^12. So the A.P is in fact an increasing one. :)

Kudos Please... If my post helped.


And how do you exactly interpret this? :shock:

question clearly says: "each term is 12^11 less than the previous term" . This could be true "ONLY IF" its a decreasing AP. Unless you are counting from right to left? :P

for example in 10, 8, 6, 4... each term is 2 less than the previous term
_________________

Lets Kudos!!! ;-)
Black Friday Debrief

Moderator
Moderator
User avatar
Joined: 02 Jul 2012
Posts: 1227
Location: India
Concentration: Strategy
GMAT 1: 740 Q49 V42
GPA: 3.8
WE: Engineering (Energy and Utilities)
Followers: 70

Kudos [?]: 745 [0], given: 116

Premium Member
Re: In a sequence of 12 numbers, each term, except for the first [#permalink] New post 06 Nov 2012, 01:00
Haha... Yes.. I was considering the A.P as 12^11, 12^11+12^11,12^11+12^11+12^11 and so on with ther 12th term being 12^11 + 11*12^12... :).. I could be wrong though...
_________________

Did you find this post helpful?... Please let me know through the Kudos button.

Thanks To The Almighty - My GMAT Debrief

GMAT Reading Comprehension: 7 Most Common Passage Types

Intern
Intern
avatar
Joined: 25 Jun 2012
Posts: 36
Followers: 0

Kudos [?]: 25 [0], given: 4

Re: In a sequence of 12 numbers, each term, except for the first [#permalink] New post 01 Dec 2012, 17:09
12 terms

1 of the 12 term is 12^12
11 of the 12 terms are 12^11

12^12- 12^11(11)

12^11(12-1(11))

12^11(12-11)

12^11
3 KUDOS received
Manager
Manager
avatar
Joined: 01 Jan 2013
Posts: 68
Location: India
Followers: 0

Kudos [?]: 12 [3] , given: 130

GMAT ToolKit User CAT Tests
Re: In a sequence of 12 numbers, each term, except for the first [#permalink] New post 23 Aug 2013, 23:40
3
This post received
KUDOS
In a sequence of 12 numbers, each term, except for the first one, is 12^11 less than the previous term. If the greatest term in the sequence is 12^12, what is the smallest term in the sequence?

A. −12^11
B. 0
C. 12^11
D. 11·12^11
E. 12^12


common Difference= 12^11
Last term = 12^12
Last term = First Term + last Term X common difference.
12^11= First term + 12^12 X 12^11
First term=12^11 - 12^12 X 12^11
First term=12^11(12-11)
First term=12^11
OA-C
1 KUDOS received
Intern
Intern
avatar
Joined: 02 Mar 2010
Posts: 18
Followers: 0

Kudos [?]: 8 [1] , given: 16

GMAT ToolKit User CAT Tests
Re: In a sequence of 12 numbers, each term, except for the first [#permalink] New post 24 Sep 2013, 16:48
1
This post received
KUDOS
Points to note in this problem:
1) We have 12 terms
2) Greatest value is 12^12
3) Every other value decreases by 12^11
If we can notice that 12 * 12^11 = 12^12, we can conclude that the smallest value must be 12^11 without doing any math.

Here's the underlying concept:
3^5 + 3^5 + 3^5 = 3*3^5 = 3^6
OR 3^6 - 3^5 - 3^5 = 3^5. --> So if this were a set of "3" terms, it could be {3(3^5), 2(3^5), 3^5} OR {3^6, 2*3^5, 3^5}

Therefore, in this case,
12^11 + 12^11 +...(12 times) = 12*12^11 = 12^12.
OR 12^12 - 11 ( 12^11) = 12^11.
So the smallest value must be 12^11.

Hope this helps..
Re: In a sequence of 12 numbers, each term, except for the first   [#permalink] 24 Sep 2013, 16:48
    Similar topics Author Replies Last post
Similar
Topics:
1 Experts publish their posts in the topic In a sequence of 40 numbers, each term, except for the first anon1 2 20 Nov 2012, 17:18
In the sequence S of numbers, each term after the first two conan9118 3 30 May 2011, 04:54
In a sequence of numbers in which each term after the first gmat620 4 14 Nov 2009, 06:38
In a sequence of numbers in which each term after the first Ferihere 3 25 Sep 2007, 05:32
In a sequence of numbers in which each term after the first Jamesk486 2 31 May 2007, 05:42
Display posts from previous: Sort by

In a sequence of 12 numbers, each term, except for the first

  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®.