BREAKING: Target Test Prep releases Brand New 2026 On Demand GMAT prep course

Redeem

sequence series.

This topic has expert replies
Post new topic Post Reply
Previous Topic Next Topic
User avatar
Legendary Member
Posts: 866
Joined: Mon Aug 02, 2010 6:46 pm
Location: Gwalior, India
Thanked: 31 times

sequence series.

by goyalsau » Sun Dec 05, 2010 3:46 am
There is a sequence of numbers whose nth term is tn. It is given that Tn = ( (Tn - 1) - 1)^2 + 1, where n is a positive integer greater than 1. If T1 = 3, what is the product of the first 10 terms of the sequence?

(Tn - 1)- Previous Term from Tn



(2^1023) - 1

(2^1024) - 1

(2^512) - 1

(2^2048) - 1

(2^1025) - 1
Last edited by goyalsau on Sun Dec 05, 2010 5:39 pm, edited 1 time in total.
Saurabh Goyal
[email protected]
-------------------------


EveryBody Wants to Win But Nobody wants to prepare for Win.
Top
Source: — Problem Solving |
Master | Next Rank: 500 Posts
Posts: 437
Joined: Sat Nov 22, 2008 5:06 am
Location: India
Thanked: 50 times
Followed by:1 members
GMAT Score:580

by beat_gmat_09 » Sun Dec 05, 2010 10:17 am
Whats the source of this question ?
looks as if this needs applying binomial theorem or something !
Hope is the dream of a man awake
Top
User avatar
Junior | Next Rank: 30 Posts
Posts: 11
Joined: Fri Oct 29, 2010 3:25 am

by oddball » Sun Dec 05, 2010 10:23 am
I think there is some problem with the question or options. Here is how I approached...
Attachments
Sequence.docx
(14 KiB) Downloaded 84 times
Top
User avatar
Legendary Member
Posts: 866
Joined: Mon Aug 02, 2010 6:46 pm
Location: Gwalior, India
Thanked: 31 times

by goyalsau » Sun Dec 05, 2010 11:05 am
This is the solution , that they provided, But i am not able to understand How they solve the Equation......

Once they reach the value of T10 = 2^512 + 1
Attachments
Untitled.jpg
Saurabh Goyal
[email protected]
-------------------------


EveryBody Wants to Win But Nobody wants to prepare for Win.
Top
User avatar
Junior | Next Rank: 30 Posts
Posts: 11
Joined: Fri Oct 29, 2010 3:25 am

by oddball » Sun Dec 05, 2010 11:10 am
goyalsau wrote:There is a sequence of numbers whose nth term is tn. It is given that Tn = ( (Tn - 1) - 1)2 + 1, where n is a positive integer greater than 1. If T1 = 3, what is the product of the first 10 terms of the sequence?
You provided wrong question dude!

In the solution you provided 2 is the power of T(n-1), not multiplied with it!
Top
User avatar
Legendary Member
Posts: 866
Joined: Mon Aug 02, 2010 6:46 pm
Location: Gwalior, India
Thanked: 31 times

by goyalsau » Sun Dec 05, 2010 5:40 pm
oddball wrote:
goyalsau wrote:There is a sequence of numbers whose nth term is tn. It is given that Tn = ( (Tn - 1) - 1)2 + 1, where n is a positive integer greater than 1. If T1 = 3, what is the product of the first 10 terms of the sequence?
You provided wrong question dude!

In the solution you provided 2 is the power of T(n-1), not multiplied with it!
Thanks Buddy, I edited the question.
Saurabh Goyal
[email protected]
-------------------------


EveryBody Wants to Win But Nobody wants to prepare for Win.
Top

GMAT/MBA Expert

User avatar
GMAT Instructor
Posts: 1179
Joined: Sun Apr 11, 2010 9:07 pm
Location: Milpitas, CA
Thanked: 447 times
Followed by:88 members

by Rahul@gurome » Mon Dec 06, 2010 3:49 am
goyalsau wrote:There is a sequence of numbers whose nth term is tn. It is given that Tn = ( (Tn - 1) - 1)^2 + 1, where n is a positive integer greater than 1. If T1 = 3, what is the product of the first 10 terms of the sequence?

(Tn - 1)- Previous Term from Tn
Here is the solution. The approach is same as the provided solution. But I tried to give a detailed explanation.
Image

Let me know if you have any doubt.
Rahul Lakhani
Quant Expert
Gurome, Inc.
https://www.GuroMe.com
On MBA sabbatical (at ISB) for 2011-12 - will stay active as time permits
1-800-566-4043 (USA)
+91-99201 32411 (India)
Top
Legendary Member
Posts: 1119
Joined: Fri May 07, 2010 8:50 am
Thanked: 29 times
Followed by:3 members

by diebeatsthegmat » Mon Dec 06, 2010 11:51 am
Rahul@gurome wrote:
goyalsau wrote:There is a sequence of numbers whose nth term is tn. It is given that Tn = ( (Tn - 1) - 1)^2 + 1, where n is a positive integer greater than 1. If T1 = 3, what is the product of the first 10 terms of the sequence?

(Tn - 1)- Previous Term from Tn
Here is the solution. The approach is same as the provided solution. But I tried to give a detailed explanation.
Image

Let me know if you have any doubt.
yes, i did the same but its so time consuming.... hey rahul, do you think this kind of time-consuming math will be on test??? :(
Top
User avatar
Legendary Member
Posts: 866
Joined: Mon Aug 02, 2010 6:46 pm
Location: Gwalior, India
Thanked: 31 times

by goyalsau » Mon Dec 06, 2010 7:14 pm
diebeatsthegmat wrote:
Rahul@gurome wrote:
goyalsau wrote:There is a sequence of numbers whose nth term is tn. It is given that Tn = ( (Tn - 1) - 1)^2 + 1, where n is a positive integer greater than 1. If T1 = 3, what is the product of the first 10 terms of the sequence?

(Tn - 1)- Previous Term from Tn
Here is the solution. The approach is same as the provided solution. But I tried to give a detailed explanation.
Image

Let me know if you have any doubt.
yes, i did the same but its so time consuming.... hey rahul, do you think this kind of time-consuming math will be on test??? :(
Gmat is a adaptive test, Once your perform good on the test, Question will be harder,

According to me Definition of Difficult problem is not that they are difficult. It is that we are not much familiar with the concept, Because This problem could have been solved in less than 2 minutes If one can realize the trick of 2^1 - 1 ,
Saurabh Goyal
[email protected]
-------------------------


EveryBody Wants to Win But Nobody wants to prepare for Win.
Top
Post new topic Post Reply
• Page 1 of 1