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.

It appears that you are browsing the GMAT Club forum unregistered!

Signing up is free, quick, and confidential.
Join other 350,000 members and get the full benefits of GMAT Club

Registration gives you:

Tests

Take 11 tests and quizzes from GMAT Club and leading GMAT prep companies such as Manhattan GMAT,
Knewton, and others. All are free for GMAT Club members.

Applicant Stats

View detailed applicant stats such as GPA, GMAT score, work experience, location, application
status, and more

Books/Downloads

Download thousands of study notes,
question collections, GMAT Club’s
Grammar and Math books.
All are free!

Thank you for using the timer!
We noticed you are actually not timing your practice. Click the START button first next time you use the timer.
There are many benefits to timing your practice, including:

If the sequence x1, x2, x3, ... xn, ... is such that x1 = 3 [#permalink]
25 Mar 2006, 13:50

00:00

A

B

C

D

E

Difficulty:

65% (hard)

Question Stats:

70% (03:35) correct
30% (03:36) wrong based on 30 sessions

If the sequence \(x_1\), \(x_2\), \(x_3\), ..., \(x_n\), ... is such that \(x_1 = 3\) and \(x_{n+1} = 2x_n - 1\) for \(n\geq1\), then \(x_{20} - x_{19}\) equals which of the following?

A. 2^19 B. 2^20 C. 2^21 D. (2^20) - 1 E. (2^21) - 1

Well the answer seems to be 2^19 and A (although your A states 219). Just write down the first elements and compute the differences.

x1=3 x2=5 x3=9 x4=17

So x2=x1+2^1 x3=x2+2^2 x4=x3+2^3 ... and x20=x19+2^19, so

x20-x19=2^19.

sorry how did you get x2 =5 and so on? I'm not even understanding the question....x (n+1)=2x(n)-1......isnt this the questions? then how does everything goes into powers of two? Please help!

Well the answer seems to be 2^19 and A (although your A states 219). Just write down the first elements and compute the differences.

x1=3 x2=5 x3=9 x4=17

So x2=x1+2^1 x3=x2+2^2 x4=x3+2^3 ... and x20=x19+2^19, so

x20-x19=2^19.

sorry how did you get x2 =5 and so on? I'm not even understanding the question....x (n+1)=2x(n)-1......isnt this the questions? then how does everything goes into powers of two? Please help!

If the sequence \(x_1\), \(x_2\), \(x_3\), ..., \(x_n\), ... is such that \(x_1 = 3\) and \(x_{n+1} = 2x_n - 1\) for \(n\geq1\), then \(x_{20} - x_{19}\) equals which of the following?

A. 2^19 B. 2^20 C. 2^21 D. (2^20) - 1 E. (2^21) - 1

We have the sequence \(x_1\), \(x_2\), \(x_3\), …, \(x_n,\)… \(x_1=3\) and \(x_{n+1}=2x_n - 1\) for \(n\geq1\).

Originally, I was supposed to have an in-person interview for Yale in New Haven, CT. However, as I mentioned in my last post about how to prepare for b-school interviews...

Hi Starlord, As far as i'm concerned, the assessments look at cognitive and emotional traits - they are not IQ tests or skills tests. The games are actually pulled from...

Interested in applying for an MBA? In the fourth and final part of our live QA series with guest expert Chioma Isiadinso, co-founder of consultancy Expartus and former admissions...

The 2015 Pan American Games and more than 6,000 athletes have come to Toronto. With them they have brought a great positive vibe and it made me think...