It is currently 23 Feb 2018, 00:44

### 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

# The numbers from 1 to 37 are written in a line from left to

Author Message
Senior Manager
Joined: 28 Aug 2006
Posts: 303
The numbers from 1 to 37 are written in a line from left to [#permalink]

### Show Tags

25 Aug 2008, 00:21
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.

The numbers from 1 to 37 are written in a line from left to right say
n1,n2,......n37 such that each number divides the sum of all its previous numbers. If n1=37 and n2=1 find the value of n3-n37.

1) 16 2)-16 3)17 4)15 5)None of these
_________________
Manager
Joined: 14 Jun 2008
Posts: 162
Re: PS: Solve this..........for 700+ aspirants [#permalink]

### Show Tags

25 Aug 2008, 01:39
cicerone wrote:
The numbers from 1 to 37 are written in a line from left to right say
n1,n2,......n37 such that each number divides the sum of all its previous numbers. If n1=37 and n2=1 find the value of n3-n37.

1) 16 2)-16 3)17 4)15 5)None of these

we know that the last number should be a factor all the numbers summed up i.e sum(1... 37) - n37

sum(1... 37) = (37*38)/2
= 37 * 19
= 703

we know that 19 is a factor of 703.
but if 19 is the last number, the sum of the previous numbers = 703-19 (which is still a multiple of 19), so the guess that 19 is a still a potential for n37.
note that 703 is not a multiple of 2 or 3, therefore, they cannot n37.
and no factors of 2 or 3 can be n37
similarly 5/7/11 cannot be n37 (at this point i stopped checking for prime numbers, but ideally should continue till 19)

we know n1 = 37
n2 = 1

therefore, n1 + n2 = 38
only factors of this are 2 and 19.

=> n3 = 2

n3 - n37 = 2 - 19
= -17

Hence None of these

E)

OA plz
Re: PS: Solve this..........for 700+ aspirants   [#permalink] 25 Aug 2008, 01:39
Display posts from previous: Sort by