Check GMAT Club Decision Tracker for the Latest School Decision Releases https://gmatclub.com/AppTrack

 It is currently 23 May 2017, 08:41

### 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

# Ps-Gmat prep

Author Message
Intern
Joined: 02 Oct 2006
Posts: 39
Followers: 0

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

### Show Tags

03 Nov 2006, 21:37
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.

Q2. In the arithmetic sequence T1, T2, T3, â€¦â€¦.Tn,â€¦..,T1=23 and Tn=Tn-1 -3 for eah n>1. when tn = -4 what is value of n?

a.-1
b.7
c.10
d.14
e.20

wud appreciate it if someone can explain how.
Senior Manager
Joined: 30 Aug 2006
Posts: 374
Followers: 3

Kudos [?]: 68 [0], given: 0

### Show Tags

03 Nov 2006, 21:49
I think its a good idea to understand how to derive a sequence, but in this case there is less room for error and stress if you just write the numbers down.

If T1=23, Tn-1 - 3 means -3 for each successive term, so:

T1 = 23
T2=20
17
14
11
8
5
2
-1
T10=-4

so 10.
Intern
Joined: 02 Oct 2006
Posts: 39
Followers: 0

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

### Show Tags

03 Nov 2006, 22:20
Thanks guys. was trying to work out the problem by sequence. which as u can see i wasn't able to set up properly. but its nice to know that could have solved it without working out sequence.
SVP
Joined: 01 May 2006
Posts: 1796
Followers: 9

Kudos [?]: 154 [0], given: 0

### Show Tags

04 Nov 2006, 03:56
***** Reposted followring some troubles ******

One way is to identify a pattern.

Since Tn=Tn-1 -3, we have

o T2=T1 -3
o T3=T2 -3 = T1 - 3*2
o T4=T3 -3 = T1 - 3*3

Thus, Tn=T1 -3*(n-1)

Tn=T1 -3*(n-1)
<=> -4 = 23 - 3*(n-1)
<=> n-1 = 27/3
<=> n = 10
04 Nov 2006, 03:56
Display posts from previous: Sort by