For all integers n n = n*(n-1). What is the value of x ? 1 x : DS Archive
Check GMAT Club Decision Tracker for the Latest School Decision Releases http://gmatclub.com/AppTrack

 It is currently 20 Jan 2017, 19:37

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

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

Events & Promotions

Events & Promotions in June
Open Detailed Calendar

For all integers n n = n*(n-1). What is the value of x ? 1 x

Author Message
Manager
Joined: 18 Aug 2005
Posts: 85
Location: Italy, Rome caput mundi
Followers: 1

Kudos [?]: 40 [0], given: 0

For all integers n n = n*(n-1). What is the value of x ? 1 x [#permalink]

Show Tags

12 Sep 2005, 08:58
00:00

Difficulty:

(N/A)

Question Stats:

0% (00:00) correct 0% (00:00) wrong based on 0 sessions

HideShow timer Statistics

This topic is locked. If you want to discuss this question please re-post it in the respective forum.

For all integers n nÂ°= n*(n-1). What is the value of xÂ°?

1 xÂ°=x
2 (x-1)Â°=x-2

please...indicate how long it took you to work it out..grazie=)
_________________

"To win the battle you need to last 15 minutes longer than your enemies"

Current Student
Joined: 28 Dec 2004
Posts: 3384
Location: New York City
Schools: Wharton'11 HBS'12
Followers: 15

Kudos [?]: 282 [0], given: 2

Show Tags

12 Sep 2005, 09:05
D it is...

x=2

VP
Joined: 22 Aug 2005
Posts: 1120
Location: CA
Followers: 1

Kudos [?]: 102 [0], given: 0

Show Tags

12 Sep 2005, 09:20
B.
I messed up in algebra.

Given: n0 = n * (n - 1) ------ (a)

i)
x0 = x
from (a), substitute value od x0:
x* (x - 1) = x

As x can be 0 (its integer), we cannot divide this equation. Simplifying:
x ^ 2 - x = x
x ^ 2 - 2 x = 0
we cannot solve this for x, and therefore cannot compute x0.

ii) (x - 1)0 = x - 2
from (a)
(x - 1) ( x - 2) = (x - 2)

x^2 - 4x + 4 = 0

or x = 2.

Last edited by duttsit on 12 Sep 2005, 09:55, edited 1 time in total.
Manager
Joined: 15 Jul 2005
Posts: 105
Followers: 1

Kudos [?]: 9 [0], given: 0

Show Tags

12 Sep 2005, 09:32

i go with (b)

statement I: x(x-1)=x
x^2-2x=0
x(x-2)=0

x = 0 or x=2... insufficient.

statement II: (x-1)(x-2)=x-2
instead of opening it out, we can tell that x-1=1 or x = 2, thus, sufficient.
Senior Manager
Joined: 30 Oct 2004
Posts: 284
Followers: 1

Kudos [?]: 62 [0], given: 0

Show Tags

12 Sep 2005, 10:45
B) chets method.
Less than a minute.
_________________

-Vikram

Manager
Joined: 18 Aug 2005
Posts: 85
Location: Italy, Rome caput mundi
Followers: 1

Kudos [?]: 40 [0], given: 0

Show Tags

13 Sep 2005, 07:26
OA i s b..thanks everyone
_________________

"To win the battle you need to last 15 minutes longer than your enemies"

13 Sep 2005, 07:26
Display posts from previous: Sort by