It is currently 23 Mar 2018, 11:57

### 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

# If n is a positive integer and r is the remainder when 4+7n

Author Message
Intern
Joined: 12 Jul 2006
Posts: 8
If n is a positive integer and r is the remainder when 4+7n [#permalink]

### Show Tags

13 Oct 2008, 19:57
00:00

Difficulty:

(N/A)

Question Stats:

0% (00:00) correct 0% (00:00) wrong based on 0 sessions

### HideShow timer Statistics

If n is a positive integer and r is the remainder when 4+7n is divided by 3, what is the value of r?

1) n+1 is divisible by 3

2) n > 20

--== Message from GMAT Club Team ==--

This is not a quality discussion. It has been retired.

If you would like to discuss this question please re-post it in the respective forum. Thank you!

To review the GMAT Club's Forums Posting Guidelines, please follow these links: Quantitative | Verbal Please note - we may remove posts that do not follow our posting guidelines. Thank you.
SVP
Joined: 29 Aug 2007
Posts: 2452

### Show Tags

13 Oct 2008, 21:09
udribat wrote:
If n is a positive integer and r is the remainder when 4+7n is divided by 3, what is the value of r?

1) n+1 is divisible by 3

2) n > 20

A.

1: n+1 = 3k, where k is an integer. so if n is divided by 3, the reminder is 2. then when 7n is divided by 3, reminder is 2. so 2+4 is 6. then r = 0.

2: n > 20 tells nothing. nsf.
_________________

Gmat: http://gmatclub.com/forum/everything-you-need-to-prepare-for-the-gmat-revised-77983.html

GT

Manager
Joined: 01 Jan 2008
Posts: 221
Schools: Booth, Stern, Haas

### Show Tags

13 Oct 2008, 21:19
GMAT TIGER wrote:
udribat wrote:
If n is a positive integer and r is the remainder when 4+7n is divided by 3, what is the value of r?

1) n+1 is divisible by 3

2) n > 20

A.

1: n+1 = 3k, where k is an integer. so if n is divided by 3, the reminder is 2. then when 7n is divided by 3, reminder is 2. so 2+4 is 6. then r 0.
2: n > 20 tells nothing. nsf.

everything is correct, just wanted to add that (4+7n)/3=4/3+7n/3=4/3+2
SVP
Joined: 29 Aug 2007
Posts: 2452

### Show Tags

13 Oct 2008, 22:03
udribat wrote:
If n is a positive integer and r is the remainder when 4+7n is divided by 3, what is the value of r?

1) n+1 is divisible by 3

2) n > 20

alternatively:

1: n + 1 = 3k where k is an integer.
4 + 7n = 1+1+1+1+n+n+n+n+3n = 4(1+n) + 3n

in the above expression, 4(1+n) is divisible by 3, r is 0 for this one. 3n is less than 3(n+1) or (3n + 3) by 3. if n+1 is divisible by 3, then (3n+3) is also divisibly by 3. also divisibly by 3 is any addition or substraction of any value that is multiple of 3.

so (3n + 3) - 3 = 3n, whcih is also divisibly by 3. so r = 0.

2: n > 20 doesnot tell much about its divisibility by 3.
_________________

Gmat: http://gmatclub.com/forum/everything-you-need-to-prepare-for-the-gmat-revised-77983.html

GT

SVP
Joined: 29 Aug 2007
Posts: 2452

### Show Tags

13 Oct 2008, 22:06
kazakhb wrote:
GMAT TIGER wrote:
udribat wrote:
If n is a positive integer and r is the remainder when 4+7n is divided by 3, what is the value of r?

1) n+1 is divisible by 3

2) n > 20

A.

1: n+1 = 3k, where k is an integer. so if n is divided by 3, the reminder is 2. then when 7n is divided by 3, reminder is 2. so 2+4 is 6. then r 0.
2: n > 20 tells nothing. nsf.

everything is correct, just wanted to add that (4+7n)/3 = 4/3 + 7n/3 = 4/3 + 2

check again the highlighted part, whcih is not correct and should be (4/3 + 2/3), above.
_________________

Gmat: http://gmatclub.com/forum/everything-you-need-to-prepare-for-the-gmat-revised-77983.html

GT

SVP
Joined: 17 Jun 2008
Posts: 1502

### Show Tags

13 Oct 2008, 22:45
udribat wrote:
If n is a positive integer and r is the remainder when 4+7n is divided by 3, what is the value of r?

1) n+1 is divisible by 3

2) n > 20

From stmt1: n + 1 = 3x for x = 0, 1,2,3,....
OR, n = 3x - 1

Thus, 7n + 4 = (21x - 3) and this is divisible by 3 for any value of x. Hence, sufficient.

Stmt2 is not sufficient.
Manager
Joined: 01 Jan 2008
Posts: 221
Schools: Booth, Stern, Haas

### Show Tags

14 Oct 2008, 01:45
Quote:

check again the highlighted part, whcih is not correct and should be (4/3 + 2/3), above.

ohhh, right, man; my mistake
SVP
Joined: 29 Aug 2007
Posts: 2452

### Show Tags

14 Oct 2008, 07:21
kazakhb wrote:
Quote:

check again the highlighted part, whcih is not correct and should be (4/3 + 2/3), above.

ohhh, right, man; my mistake

check again the highlighted part, (which is not correct).
_________________

Gmat: http://gmatclub.com/forum/everything-you-need-to-prepare-for-the-gmat-revised-77983.html

GT

Manager
Joined: 01 Jan 2008
Posts: 221
Schools: Booth, Stern, Haas

### Show Tags

14 Oct 2008, 21:08
GMAT TIGER wrote:
kazakhb wrote:
Quote:

check again the highlighted part, whcih is not correct and should be (4/3 + 2/3), above.

ohhh, right, man; my mistake

check again the highlighted part, (which is not correct).

really?

--== Message from GMAT Club Team ==--

This is not a quality discussion. It has been retired.

If you would like to discuss this question please re-post it in the respective forum. Thank you!

To review the GMAT Club's Forums Posting Guidelines, please follow these links: Quantitative | Verbal Please note - we may remove posts that do not follow our posting guidelines. Thank you.
Re: DS Problem   [#permalink] 14 Oct 2008, 21:08
Display posts from previous: Sort by