Find all School-related info fast with the new School-Specific MBA Forum

 It is currently 17 Apr 2015, 19:24

### 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

# What is the missing term? 1, 7, 17, 31, ? , 71, 97 ...

 Question banks Downloads My Bookmarks Reviews Important topics
Author Message
TAGS:
Senior Manager
Joined: 04 Mar 2007
Posts: 442
Followers: 1

Kudos [?]: 16 [0], given: 0

What is the missing term? 1, 7, 17, 31, ? , 71, 97 ...  [#permalink]  05 May 2007, 10:52
00:00

Difficulty:

(N/A)

Question Stats:

0% (00:00) correct 0% (00:00) wrong based on 0 sessions
What is the missing term?
1, 7, 17, 31, ? , 71, 97 ...

A) 45
B) 49
C) 51
D) 53
E) 59
Manager
Joined: 23 Dec 2006
Posts: 136
Followers: 1

Kudos [?]: 11 [0], given: 0

[#permalink]  05 May 2007, 11:23
I'm stuck between D and E, the the only primes in the list. I'm going with D for an arbitrary reason.

Edit: E) 59. The difference between the numbers increases by 4 each time.
Manager
Joined: 09 Sep 2004
Posts: 166
Followers: 1

Kudos [?]: 1 [0], given: 0

[#permalink]  11 May 2007, 21:30
The answer is B - 49

The difference increases by 4

1,7= 6

7,17= 10

17,31= 14

31,x=18

x,71 = 22

71, 97=26

31+18=49

Hope this helps!!
Director
Joined: 18 Jul 2006
Posts: 531
Followers: 1

Kudos [?]: 28 [0], given: 0

[#permalink]  11 May 2007, 22:19
49..Doesn't looks like GMAT question though...
Senior Manager
Joined: 04 Mar 2007
Posts: 442
Followers: 1

Kudos [?]: 16 [0], given: 0

[#permalink]  12 May 2007, 01:33
Hi

The OA is B.
The formula of n-term here is 2*n^2 - 1
VP
Joined: 08 Jun 2005
Posts: 1147
Followers: 6

Kudos [?]: 127 [0], given: 0

[#permalink]  12 May 2007, 02:43
Juaz wrote:
49..Doesn't looks like GMAT question though...

I agree - doesn't look like a GMAT question.

1,7,17,31,x,71,97

looking for an avarege

(224+x)/7 = integer

since 224/7 = 32

x/7 has to be an integer

so the answer has to be (B) meaning 49

maybe not a GMAT question but nevertheless a good one.

[#permalink] 12 May 2007, 02:43
Similar topics Replies Last post
Similar
Topics:
S97-17 1 16 Sep 2014, 00:52
M17-31 1 16 Sep 2014, 00:02
6 What is the value of 2x^2 - 2.4x - 1.7 for x = 0.7 ? 5 03 Mar 2014, 00:16
What is the sum of 1+3+5...+71+73+75 8 14 Feb 2007, 14:34
What's the next term of this series?! 1,2,3,7,46 .... 2 09 Nov 2005, 23:00
Display posts from previous: Sort by

# What is the missing term? 1, 7, 17, 31, ? , 71, 97 ...

 Question banks Downloads My Bookmarks Reviews Important topics

 Powered by phpBB © phpBB Group and phpBB SEO 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®.