It is currently 19 Jan 2018, 09:27

### 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

# A sequence of numbers is given by the rule an = (an – 1)^2. What is a5

 new topic post reply Question banks Downloads My Bookmarks Reviews Important topics
Author Message
TAGS:

### Hide Tags

Math Expert
Joined: 02 Sep 2009
Posts: 43324

Kudos [?]: 139504 [0], given: 12791

A sequence of numbers is given by the rule an = (an – 1)^2. What is a5 [#permalink]

### Show Tags

29 Oct 2017, 00:56
00:00

Difficulty:

25% (medium)

Question Stats:

74% (00:41) correct 26% (00:28) wrong based on 39 sessions

### HideShow timer Statistics

A sequence of numbers is given by the rule $$a_n = (a_{n – 1})^2$$. What is $$a_5$$?

(1) $$a_1 = –1$$
(2) $$a_3 = 1$$
[Reveal] Spoiler: OA

_________________

Kudos [?]: 139504 [0], given: 12791

Math Expert
Joined: 02 Aug 2009
Posts: 5529

Kudos [?]: 6432 [0], given: 122

Re: A sequence of numbers is given by the rule an = (an – 1)^2. What is a5 [#permalink]

### Show Tags

29 Oct 2017, 03:36
Bunuel wrote:
A sequence of numbers is given by the rule $$a_n = (a_{n – 1})^2$$. What is $$a_5$$?

(1) $$a_1 = –1$$
(2) $$a_3 = 1$$

$$a_n = (a_{n – 1})^2$$ tells us that each term is linked to another term..
so knowing ANY number in the sequence can give us the value of ALL terms in the sequence ..

we are looking for $$a_5$$, so knowing any other term will help us in knowing it...

Both statements give us one value of a term, so EACH statement is sufficient

D
_________________

Absolute modulus :http://gmatclub.com/forum/absolute-modulus-a-better-understanding-210849.html#p1622372
Combination of similar and dissimilar things : http://gmatclub.com/forum/topic215915.html

BANGALORE/-

Kudos [?]: 6432 [0], given: 122

Manager
Joined: 15 Aug 2016
Posts: 57

Kudos [?]: 4 [0], given: 82

Re: A sequence of numbers is given by the rule an = (an – 1)^2. What is a5 [#permalink]

### Show Tags

29 Oct 2017, 09:57
Both Statements are sufficient.

If a1 is given we can calculate a2,a3,a4 and then a5.

If a3 is given, we can calculate a4 and then a5.

IMO:D

Kudos [?]: 4 [0], given: 82

Re: A sequence of numbers is given by the rule an = (an – 1)^2. What is a5   [#permalink] 29 Oct 2017, 09:57
Display posts from previous: Sort by

# A sequence of numbers is given by the rule an = (an – 1)^2. What is a5

 new topic post reply Question banks Downloads My Bookmarks Reviews Important topics

 Powered by phpBB © phpBB Group | Emoji artwork provided by EmojiOne 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®.