a = 2 - (1/a) - The Beat The GMAT Forum - Expert GMAT Help & MBA Admissions Advice

a = 2 - (1/a)

Expert replies

sanju09: GMAT Instructor; Posts: 3650; Joined: Wed Jan 21, 2009 4:27 amFollowed by: 80 members; Location: India; Thanked: 267 times; GMAT Score:760

by sanju09 » Fri Feb 05, 2010 6:25 am

If a = 2 - (1/a), what is the value of integer n?

(1) a = 2^n.

(2) a^n = 1/(a^n).

The mind is everything. What you think you become. -Lord Buddha

Sanjeev K Saxena
Quantitative Instructor
The Princeton Review - Manya Abroad
Lucknow-226001

www.manyagroup.com

Like this post

Source: Beat The GMAT — Data Sufficiency | Fri Feb 05, 2010 6:25 am

ajith: Legendary Member; Posts: 1275; Joined: Thu Sep 21, 2006 11:13 pmFollowed by: 2 members; Location: Arabian Sea; Thanked: 125 times

by ajith » Fri Feb 05, 2010 6:46 am

sanju09 wrote:If a = 2 - (1/a), what is the value of integer n?

(1) a = 2^n.

(2) a^n = 1/(a^n).

a^2 = 2a -1
a^2 -2a +1
(a-1)^2=0
a=1
[assumption a is not zero)

1) a= 2^n

n=0 Sufficient

2) since a= 1
a^n = 1/(a^n) for all values of n; insufficient

A

Always borrow money from a pessimist, he doesn't expect to be paid back.

Like this post

Post new topic Post Reply

• Page 1 of 1

GMAT Course Reviews

560 reviews

1168 reviews

431 reviews

359 reviews

147 reviews

5/5

5 Star (560 Reviews)

"Target Test Prep is the closest to the official version of the GMAT exam, about 99% accuracy in terms of the quality and quantity of information. The course has excellently created singular sets of focused lessons and tests for every possible topic that one could come across in the official GMAT exam."

"The TTP course maximizes the efficiency of the time you spend studying. It will take time and effort but I could almost guarantee that if you complete the course exactly as it is laid out you will get an amazing score. They also have a very responsive team willing to help with any questions you might have."

"TTP has two things that I think no other test prep company offers: A teaching approach that reinforces understanding and an attitude that will give you the mental preparedness needed to succeed on the test. TTP gives you a deep understanding of the concept you need to know while teaching you how to think."

Write a Review