It is currently 18 Oct 2017, 17:43

### 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

# ds:remainder

Author Message
Manager
Joined: 14 Jun 2007
Posts: 168

Kudos [?]: 9 [0], given: 0

Location: Vienna, Austria

### Show Tags

29 Oct 2008, 03:11
1
This post was
BOOKMARKED
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.

guys

What is the remainder when the positive integer x is divided by 8?

1. when x is divided by 12, the remainder is 5.
2. when x is divided by 18, the remainder is 7.

is it C or E ?

cheers

Kudos [?]: 9 [0], given: 0

SVP
Joined: 17 Jun 2008
Posts: 1534

Kudos [?]: 279 [1], given: 0

### Show Tags

29 Oct 2008, 03:34
1
KUDOS
It will be E.

From stmt1: x = 12a + 5 for a = 0,1,2,3,4,......
From stmt2: x = 18b + 7 for b = 0,1,2,3,......

Combining two, 12a + 5 = 18b + 7, or 12a = 18b + 2 or, 6a = 9b + 1
or, a = (9b+1)/(2*3)

Thus, in order for a to be an integer, 9b+1 should have 2 and 3 as its factors. But, that will never be possible as if any number n has a set of factors, these will not be the factors of (n+1). Accordingly, 9b has 3 as the factor, hence 9b+1 will not have 3 as the factor and accordingly, a will not be an integer.

Hence, even after combining stmt1 and stmt2, we will not get a common number.. Hence, insufficient.

Kudos [?]: 279 [1], given: 0

VP
Joined: 30 Jun 2008
Posts: 1034

Kudos [?]: 705 [0], given: 1

### Show Tags

29 Oct 2008, 06:36
scthakur wrote:
Thus, in order for a to be an integer, 9b+1 should have 2 and 3 as its factors. But, that will never be possible as if any number n has a set of factors, these will not be the factors of (n+1). Accordingly, 9b has 3 as the factor, hence 9b+1 will not have 3 as the factor and accordingly, a will not be an integer.

Thanks scthakur .... I really never know this property .......... +1!
_________________

"You have to find it. No one else can find it for you." - Bjorn Borg

Kudos [?]: 705 [0], given: 1

SVP
Joined: 29 Aug 2007
Posts: 2472

Kudos [?]: 843 [0], given: 19

### Show Tags

29 Oct 2008, 09:25
domleon wrote:
guys

What is the remainder when the positive integer x is divided by 8?

1. when x is divided by 12, the remainder is 5.
2. when x is divided by 18, the remainder is 7.

is it C or E ?

cheers

Seem the question is wrong (or misleading) because any integer, x, when divided by 12 has reminder 5 cannot have reminder 7 when the same integer is divided by 18. the reminder could be 5 or 11 or 17. none can be reminder when x is divided by 18.

so this is a flawed question.
_________________

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

GT

Kudos [?]: 843 [0], given: 19

VP
Joined: 30 Jun 2008
Posts: 1034

Kudos [?]: 705 [0], given: 1

### Show Tags

29 Oct 2008, 09:42
GMAT TIGER wrote:
Seem the question is wrong (or misleading) because any integer, x, when divided by 12 has reminder 5 cannot have reminder 7 when the same integer is divided by 18. the reminder could be 5 or 11 or 17. none can be reminder when x is divided by 18.

so this is a flawed question.

Can you explain a bit more I seem to get the point but only partially .....
_________________

"You have to find it. No one else can find it for you." - Bjorn Borg

Kudos [?]: 705 [0], given: 1

SVP
Joined: 29 Aug 2007
Posts: 2472

Kudos [?]: 843 [0], given: 19

### Show Tags

29 Oct 2008, 13:00
amitdgr wrote:
GMAT TIGER wrote:
Seem the question is wrong (or misleading) because any integer, x, when divided by 12 has reminder 5 cannot have reminder 7 when the same integer is divided by 18. the reminder could be 5 or 11 or 17. none can be reminder when x is divided by 18.

so this is a flawed question.

Can you explain a bit more I seem to get the point but only partially .....

I meant to say X cannot have 2 values. As per the statements 1 and 2, x has 2 values and thats, as per GMAT standard, is substandard.

You do not get such questions in real test.
_________________

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

GT

Kudos [?]: 843 [0], given: 19

SVP
Joined: 17 Jun 2008
Posts: 1534

Kudos [?]: 279 [0], given: 0

### Show Tags

29 Oct 2008, 22:38
GMAT TIGER wrote:
domleon wrote:
guys

What is the remainder when the positive integer x is divided by 8?

1. when x is divided by 12, the remainder is 5.
2. when x is divided by 18, the remainder is 7.

is it C or E ?

cheers

Seem the question is wrong (or misleading) because any integer, x, when divided by 12 has reminder 5 cannot have reminder 7 when the same integer is divided by 18. the reminder could be 5 or 11 or 17. none can be reminder when x is divided by 18.

so this is a flawed question.

GT, what you say is right only when x is common between stmt1 and stmt2. But, if x is not common between stmt1 and stmt2, then what you say may not be true.

Kudos [?]: 279 [0], given: 0

SVP
Joined: 29 Aug 2007
Posts: 2472

Kudos [?]: 843 [0], given: 19

### Show Tags

30 Oct 2008, 14:14
scthakur wrote:
GMAT TIGER wrote:
domleon wrote:
guys

What is the remainder when the positive integer x is divided by 8?

1. when x is divided by 12, the remainder is 5.
2. when x is divided by 18, the remainder is 7.

is it C or E ?

cheers

Seem the question is wrong (or misleading) because any integer, x, when divided by 12 has reminder 5 cannot have reminder 7 when the same integer is divided by 18. the reminder could be 5 or 11 or 17. none can be reminder when x is divided by 18.

so this is a flawed question.

GT, what you say is right only when x is common between stmt1 and stmt2. But, if x is not common between stmt1 and stmt2, then what you say may not be true.

I said this only in the context of this question. But if x is not common between stmt1 and stmt2, then what I said is also true cuz I have not said anything when the scenerio changes.
_________________

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

GT

Kudos [?]: 843 [0], given: 19

SVP
Joined: 17 Jun 2008
Posts: 1534

Kudos [?]: 279 [0], given: 0

### Show Tags

30 Oct 2008, 22:36
GMAT TIGER wrote:
I said this only in the context of this question. But if x is not common between stmt1 and stmt2, then what I said is also true cuz I have not said anything when the scenerio changes.

Well, even in the context of this question,
stmt1 gives x = 5,17, 29, .....
stmt2 gives x = 7, 25, 43, ......

and the question is independently giving values of x in statement 1 and in statement 2. Why should the two statements provide a common value (if this is what you meant)?

Kudos [?]: 279 [0], given: 0

Re: ds:remainder   [#permalink] 30 Oct 2008, 22:36
Display posts from previous: Sort by