It is currently 18 Nov 2017, 18:34

### 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

# Product of 2 consecutive odd integers is 783. Find their

Author Message
Senior Manager
Joined: 04 Mar 2007
Posts: 431

Kudos [?]: 86 [0], given: 0

Product of 2 consecutive odd integers is 783. Find their [#permalink]

### Show Tags

21 May 2007, 11:49
00:00

Difficulty:

(N/A)

Question Stats:

100% (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.

Product of 2 consecutive odd integers is 783. Find their sum.

A) 44
B) -56
C) -76
D) 64
E) -36

Kudos [?]: 86 [0], given: 0

VP
Joined: 08 Jun 2005
Posts: 1143

Kudos [?]: 254 [0], given: 0

### Show Tags

21 May 2007, 12:49
x*(x+2) = 783 (two consecutive numbers i.e x=3,x+2=5)

x^2+2x = 783

x^2+2x-783 = 0

factoring 783

783:3
261:3
87:3
29

3*3*3*29 = 29*27

(x+29)(x-27) = 0

x can be either -29,27

if x = 27 then x+2 = 29 and 27+29 = 56

if x = -29 then x+2 = -27 and -29+(-27) = -56

the only possible answer is (B)

Kudos [?]: 254 [0], given: 0

Director
Joined: 13 Mar 2007
Posts: 542

Kudos [?]: 92 [0], given: 0

Schools: MIT Sloan

### Show Tags

23 May 2007, 00:21
factorize 783

783 = 3 x 3 x 3 x 29

hence all factors - 1,783,3,9,27,29,87,261

only two consecutive odds = 27,29

Hence B

Kudos [?]: 92 [0], given: 0

Director
Joined: 18 Jul 2006
Posts: 523

Kudos [?]: 71 [0], given: 0

Re: PS - consecutive odds [#permalink]

### Show Tags

23 May 2007, 01:03
Caas wrote:
Product of 2 consecutive odd integers is 783. Find their sum.

A) 44
B) -56
C) -76
D) 64
E) -36

As two integers are next to each other, one quick way of sloving this is look for square root of 783 = 28 appx (as 28*28 =784).

so integers could be 27 & 29 OR -27 & -29.

Kudos [?]: 71 [0], given: 0

VP
Joined: 08 Jun 2005
Posts: 1143

Kudos [?]: 254 [0], given: 0

Re: PS - consecutive odds [#permalink]

### Show Tags

23 May 2007, 01:36
Juaz wrote:
Caas wrote:
Product of 2 consecutive odd integers is 783. Find their sum.

A) 44
B) -56
C) -76
D) 64
E) -36

As two integers are next to each other, one quick way of sloving this is look for square root of 783 = 28 appx (as 28*28 =784).

so integers could be 27 & 29 OR -27 & -29.

Nice thanks ! a real time saver !

Kudos [?]: 254 [0], given: 0

Senior Manager
Joined: 04 Mar 2007
Posts: 431

Kudos [?]: 86 [0], given: 0

### Show Tags

23 May 2007, 09:01
Thank you for the discussion guys
You are all right. OA is B indeed.
For those who wonder - another way of solving it
(2n-1)*(2n+1)=783
4n^2-1=783
n^2=784/4
n=+/- 14
2n=+/- 28 ----> so the consecutive odd integers are +/- 27 and +/- 29 and their sum is +/- 56

Kudos [?]: 86 [0], given: 0

23 May 2007, 09:01
Display posts from previous: Sort by