Last visit was: 28 Apr 2026, 20:45 It is currently 28 Apr 2026, 20:45
Home
Messages
Tests
Schools
Events
Close
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
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.
Go to My Error Log Learn more
Close
Request Expert Reply
Confirm Cancel
Events & Promotions
Back to Forum
Create Topic
Sub 505 (Easy)|   Sequences|      
User avatar
adkikani
User avatar
IIM School Moderator
Joined: 04 Sep 2016
Last visit: 24 Dec 2023
Posts: 1,223
Own Kudos:
1,359
 [12]
Given Kudos: 1,207
Location: India
WE:Engineering (Other)
Posts: 1,223
Kudos: 1,359
 [12]
In a sequence of numbers in which each term is two more than the prece Updated on: 05 Sep 2023, 00:07
Originally posted by adkikani on 13 Nov 2018, 09:23.
Last edited by Bunuel on 05 Sep 2023, 00:07, edited 3 times in total.
Renamed the topic, edited the question and the tags.
5
Kudos
Add Kudos
7
Bookmarks
Bookmark this Post
00:00
Start Timer
Pause Timer
Resume Timer
Show Answer
Hide
Show
History
B
Be sure to select an answer first to save it in the Error Log before revealing the correct answer (OA)!

Difficulty:

5% (low)

Question Stats:

83% (00:34) correct 17% (00:48) wrong based on 640 sessions

History

Date
Time
Result
Not Attempted Yet
In a sequence of numbers in which each term is two more than the preceding term, what is the fourth term?

(1) Last term is 90
(2) First term is 2
ShowHide Answer
Official Answer
B
Solving this question helps. Taking a timed set of similar questions in GMAT Club Forum Quiz → is even better.
Most Helpful Reply
User avatar
Gladiator59
User avatar
Joined: 16 Sep 2016
Last visit: 18 Mar 2026
Posts: 840
Own Kudos:
2,719
 [5]
Given Kudos: 271
Status:It always seems impossible until it's done.
GMAT 1: 740 Q50 V40
GMAT 2: 770 Q51 V42
Products:
My Reviews
GMAT 2: 770 Q51 V42
Posts: 840
Kudos: 2,719
 [5]
In a sequence of numbers in which each term is two more than the prece 13 Nov 2018, 10:43
4
Kudos
Add Kudos
1
Bookmarks
Bookmark this Post
Given sequence is an arithmetic progression ( since each new term is two more than the previous). We need to find the fourth term.

St (1) Insufficient! as we do not have any info about the # of terms, we cannot be certain where the sequence begins.

St (2) Sufficient! given the first term and the difference between two terms we can determine any term of the sequence as it is an AP.

Hence Option (B) is our choice!

Best,
GLadi
adkikani
In a sequence of numbers in which each term is two more than the preceding term, what is the fourth term?


(1) Last term is 90

(2) First term is 2
 
Show more
­
General Discussion
User avatar
Salsanousi
User avatar
Joined: 19 Oct 2013
Last visit: 29 Dec 2020
Posts: 391
Own Kudos:
358
 [2]
Given Kudos: 117
Location: Kuwait
GPA: 3.2
WE:Engineering (Real Estate)
Posts: 391
Kudos: 358
 [2]
In a sequence of numbers in which each term is two more than the prece 13 Nov 2018, 10:48
2
Kudos
Add Kudos
Bookmarks
Bookmark this Post
adkikani
In a sequence of numbers in which each term is two more than the preceding term, what is the fourth term?

(1) Last term is 90

(2) First term is 2
 
Show more
\(S_n = S_n-1 + 2\)

Given that we don't know how many terms are there? it could be that the last term is actually 5 and it could be 100.. so we cannot figure out anything specific.

Insufficient.

Knowing \(S_2 = S_1 + 2 = 2 + 2 = 4\)

we can solve for it and find \(S_4 = S_3 + 2 = S_2 + 2 + 2 = S_1 + 2 + 2 + 2 = 2 + 2 + 2 + 2 = 8\)

B is sufficient.­
User avatar
dollytaneja51
User avatar
Joined: 26 Feb 2017
Last visit: 02 Apr 2019
Posts: 69
Own Kudos:
60
 [1]
Given Kudos: 14
Location: India
GPA: 3.99
Posts: 69
Kudos: 60
 [1]
In a sequence of numbers in which each term is two more than the prece 13 Nov 2018, 12:54
1
Kudos
Add Kudos
Bookmarks
Bookmark this Post
Statement 1: Last term is 90. We do not have any information regarding first term and how many terms are there? Insufficient

Statement 2: First term is 2 with this we can calculate the fourth term as it is given that each term is two more than the preceding term. Hence Sufficient

B is the right answer

Posted from my mobile device
User avatar
dave13
User avatar
Joined: 09 Mar 2016
Last visit: 15 Mar 2026
Posts: 1,086
Own Kudos:
1,138
 [1]
Given Kudos: 3,851
Posts: 1,086
Kudos: 1,138
 [1]
In a sequence of numbers in which each term is two more than the prece 16 Nov 2018, 09:14
Kudos
Add Kudos
1
Bookmarks
Bookmark this Post
FORMULA FOR FINDING # OF TERMS

\(x_n = a+d (n-1)\)

\(n\) = # of term
\(a\) = first term
\(d\) = distance between terms

As per statement ONE the last term is 90, however it is not sufficient because we dont know the first term: it can be any number.

As per statement TWO the first term is 2. Since we know as well distance between terms. we can get the FOURTH term

\(x_4 = 2+2 (n-1)\)

\(x_4 = 2+2n-2\)

\(x_4 = 2n\) plug in 4

\(x_4 = 2*4\)

\(x_4 = 8\)

B
User avatar
BrentGMATPrepNow
User avatar
Major Poster
Joined: 12 Sep 2015
Last visit: 31 Oct 2025
Posts: 6,733
Own Kudos:
36,477
 [1]
Given Kudos: 799
Location: Canada
Expert
Expert reply
Posts: 6,733
Kudos: 36,477
 [1]
In a sequence of numbers in which each term is two more than the prece 14 Feb 2020, 07:59
Kudos
Add Kudos
1
Bookmarks
Bookmark this Post
adkikani
In a sequence of numbers in which each term is two more than the preceding term, what is the fourth term?

(1) Last term is 90
(2) First term is 2
Show more

Target question: What is the value of term_4?

Statement 1: The last term is 90.
We have no idea how many terms there are in the sequence. So, the last term could be term_5 or term_9 or term_12 or . . .

Consider these two possible cases:
Case a: The last term is term_6. In this case, term_6 = 90, term_5 = 88, term_4 = 86, term_3 = 84....etc. So, the answer to the target question is term_4 = 86
Case b: The last term is term_5. In this case, term_5 = 90, term_4 = 88, term_3 = 86 ....etc. So, the answer to the target question is term_4 = 88
Since we cannot answer the target question with certainty, statement 1 is NOT SUFFICIENT

Statement 2: The first term is 2.
If term_1 = 2, then: term_2 = 4, term_3 = 6, term_4 = 8, . .. etc
The answer to the target question is term_4 = 8
Since we can answer the target question with certainty, statement 2 is SUFFICIENT

Answer: B

Cheers,
Brent
User avatar
MHIKER
User avatar
Joined: 14 Jul 2010
Last visit: 24 May 2021
Posts: 939
Own Kudos:
5,821
Given Kudos: 690
Status:No dream is too large, no dreamer is too small
Concentration: Accounting
Posts: 939
Kudos: 5,821
In a sequence of numbers in which each term is two more than the prece 15 Jan 2021, 10:36
Kudos
Add Kudos
Bookmarks
Bookmark this Post
adkikani
In a sequence of numbers in which each term is two more than the preceding term, what is the fourth term?


(1) Last term is 90

(2) First term is 2
Show more

(1) We know increment but we don't know the first term. Insufficient

(2) We know increment and the first term. sufficient.
User avatar
kungfury42
User avatar
Joined: 07 Jan 2022
Last visit: 31 May 2023
Posts: 580
Own Kudos:
518
Given Kudos: 724
Schools: NUS '25 (A)
GMAT 1: 740 Q51 V38
GPA: 4
Products:
My Reviews
Schools: NUS '25 (A)
GMAT 1: 740 Q51 V38
Posts: 580
Kudos: 518
In a sequence of numbers in which each term is two more than the prece 17 Feb 2022, 10:40
Kudos
Add Kudos
Bookmarks
Bookmark this Post
adkikani
In a sequence of numbers in which each term is two more than the preceding term, what is the fourth term?

(1) Last term is 90

(2) First term is 2
 
Show more
(1) Gives no information on the total number of terms, hence cannot determine the 4th term. Insufficient.

(2) 1st term = 2, therefore 2nd term = 4, 3rd term = 6, and 4th term = 8. Sufficient.

Hence, B.­
User avatar
bumpbot
User avatar
Non-Human User
Joined: 09 Sep 2013
Last visit: 04 Jan 2021
Posts: 38,986
Own Kudos:
1,119
Posts: 38,986
Kudos: 1,119
In a sequence of numbers in which each term is two more than the prece 08 Aug 2025, 13:30
Kudos
Add Kudos
Bookmarks
Bookmark this Post
Automated notice from GMAT Club BumpBot:

A member just gave Kudos to this thread, showing it’s still useful. I’ve bumped it to the top so more people can benefit. Feel free to add your own questions or solutions.

This post was generated automatically.
Moderators:
Bunuel
Math Expert
109950 posts
kingbucky
498 posts
Gmat860sanskar
212 posts