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

It is currently 24 May 2013, 16:13
Customize  |  Hide

If positive integer x is divided by 5, the result is p and

  Question banks Downloads My Bookmarks Reviews  
Author Message
TAGS:
3 KUDOS received
Manager
Manager
Joined: 12 Oct 2011
Posts: 136
GMAT 1: 700 Q48 V37
GMAT 2: 720 Q48 V40
Followers: 2

Kudos [?]: 37 [3] , given: 23

If positive integer x is divided by 5, the result is p and [#permalink] New post 08 Apr 2012, 03:33
3
This post received
KUDOS
00:00

Question Stats:

71% (02:19) correct 28% (01:11) wrong based on 8 sessions
If positive integer x is divided by 5, the result is p and the remainder 3. If x is divided by 11, the remainder is 3 again, what is the remainder when p is divided by 11?

(A) 0
(B) 1
(C) 2
(D) 3
(E) 4

I had to plug in numbers, how can you solve this with the remainder formula?
[Reveal] Spoiler: OA
1 KUDOS received
GMAT Club team member
User avatar
Joined: 02 Sep 2009
Posts: 11611
Followers: 1801

Kudos [?]: 9594 [1] , given: 829

Re: If positive integer x is divided by 5, the result is p [#permalink] New post 08 Apr 2012, 03:47
1
This post received
KUDOS
BN1989 wrote:
If positive integer x is divided by 5, the result is p and the remainder 3. If x is divided by 11, the remainder is 3 again, what is the remainder when p is divided by 11?

(A) 0
(B) 1
(C) 2
(D) 3
(E) 4

I had to plug in numbers, how can you solve this with the remainder formula?


If positive integer x is divided by 5, the result is p and the remainder 3: x=5p+3;
If positive integer x is divided by 11, the the remainder 3: x=11q+3;

Subtract one from another: x-x=(5p+3)-(11q+3) --> 5p=11q---> \frac{p}{q}=\frac{11}{5} --> since both p and q are integers then p mus be a multiple of 11, so it yields remainder of zero upon division by 11.

Answer: A.

Hope it's clear.
_________________

PLEASE READ AND FOLLOW: 11 Rules for Posting!!!

RESOURCES: [GMAT MATH BOOK]; 1. Triangles; 2. Polygons; 3. Coordinate Geometry; 4. Factorials; 5. Circles; 6. Number Theory

COLLECTION OF QUESTIONS:
PS: 1. Tough and Tricky questions; 2. Hard questions; 3. Hard questions part 2; 4. Standard deviation; 5. Tough Problem Solving Questions With Solutions; 6. Probability and Combinations Questions With Solutions; 7 Tough and tricky exponents and roots questions; 8 12 Easy Pieces (or not?); 9 Bakers' Dozen; 10 Algebra set. NEW!!!

DS: 1. DS tough questions; 2. DS tough questions part 2; 3. DS tough questions part 3; 4. DS Standard deviation; 5. Inequalities; 6. 700+ GMAT Data Sufficiency Questions With Explanations; 7 Tough and tricky exponents and roots questions; 8 The Discreet Charm of the DS ; 9 Devil's Dozen!!!; 10 Number Properties set. NEW!!!


What are GMAT Club Tests?
25 extra-hard Quant Tests

Find out what's new at GMAT Club - latest features and updates

Senior Manager
Senior Manager
User avatar
Status: May The Force Be With Me (D-DAY 15 May 2012)
Joined: 06 Jan 2012
Posts: 296
Location: India
Concentration: General Management, Entrepreneurship
Followers: 1

Kudos [?]: 39 [0], given: 16

Reviews Badge
Re: If positive integer x is divided by 5, the result is p and [#permalink] New post 08 Apr 2012, 05:35
I got this wrong....

I tried to plug in numbers but didn't manage to get it. Then just guessed

@ Bunuel : Kudos of the explanation
@ BN1989 : Nice questions Kudos to u too
_________________

Giving +1 kudos is a better way of saying 'Thank You'.

Manager
Manager
Status: And the Prep starts again...
Joined: 03 Aug 2010
Posts: 139
Followers: 1

Kudos [?]: 20 [0], given: 20

GMAT Tests User
Re: If positive integer x is divided by 5, the result is p and [#permalink] New post 19 Apr 2012, 23:35
Bunuel, I tried using this method below as described in

http://gmatclub.com/forum/manhattan-remainder-problem-93752.html#p721341

I got stuck. Please help

X=5P+3 , x can be 8 13 18 23...58
X=11Q+3, x can be 14,25,....58

To form the equation n=kx+r
n=55K+58

Not sure how to proceed.
_________________

My First Blog on my GMAT Journey

Arise, Awake and Stop not till the goal is reached

1 KUDOS received
Intern
Intern
User avatar
Joined: 17 Feb 2012
Posts: 23
Schools: LBS '14
Followers: 1

Kudos [?]: 10 [1] , given: 8

Re: If positive integer x is divided by 5, the result is p and [#permalink] New post 20 Apr 2012, 00:31
1
This post received
KUDOS
Since X-3 is divisible both by 5 and by 11,which are prime numbers, so P/11 or X-3/11 will always be with remainder 0
_________________

KUDOS needed URGENTLY. Thank you in advance and be ACTIVE!

GMAT Club team member
User avatar
Joined: 02 Sep 2009
Posts: 11611
Followers: 1801

Kudos [?]: 9594 [0], given: 829

Re: If positive integer x is divided by 5, the result is p and [#permalink] New post 20 Apr 2012, 03:35
ENAFEX wrote:
Bunuel, I tried using this method below as described in

http://gmatclub.com/forum/manhattan-remainder-problem-93752.html#p721341

I got stuck. Please help

X=5P+3 , x can be 8 13 18 23...58
X=11Q+3, x can be 14,25,....58

To form the equation n=kx+r
n=55K+58

Not sure how to proceed.


First of all you don't need to use that approach to solve the problem.

Next, you are making a mistake while deriving a general formula.

Positive integer x is divided by 5, the result is p and the remainder 3: x=5p+3 --> x can be: 3, 8, 13, ... Notice that the least value of x for which it gives the remainder of 3 upon division by 5 is 3 itself: 3 divided by 5 yields remainder of 3.

Positive integer x is divided by 11, the the remainder 3: x=11q+3 --> x can be: 3, 14, 25, ... Th same here the least value of x is 3: 3 divided by 11 yields remainder of 3.

General formula would be: x=55k+3.

Check the problems below for which you can use this approach:
positive-integer-n-leaves-a-remainder-of-4-after-division-by-93752.html
if-n-is-a-positive-integer-greater-than-16-is-n-a-prime-129829.html
when-positive-integer-x-is-divided-by-5-the-remainder-is-128470.html
when-n-is-divided-by-5-the-remainder-is-2-when-n-is-divided-82624.html
when-positive-integer-n-is-divided-by-5-the-remainder-is-90442.html
when-the-positive-integer-a-is-divided-by-5-and-125591.html
what-is-the-value-of-length-n-100-meter-of-wire-126500.html
a-group-of-n-students-can-be-divided-into-equal-groups-of-126384.html
when-the-positive-integer-a-is-divided-by-5-and-7-the-104480.html
positive-integer-n-leaves-a-remainder-of-4-after-division-by-93752.html
when-positive-integer-n-is-divided-by-3-the-remainder-is-86155.html

Hope it helps.
_________________

PLEASE READ AND FOLLOW: 11 Rules for Posting!!!

RESOURCES: [GMAT MATH BOOK]; 1. Triangles; 2. Polygons; 3. Coordinate Geometry; 4. Factorials; 5. Circles; 6. Number Theory

COLLECTION OF QUESTIONS:
PS: 1. Tough and Tricky questions; 2. Hard questions; 3. Hard questions part 2; 4. Standard deviation; 5. Tough Problem Solving Questions With Solutions; 6. Probability and Combinations Questions With Solutions; 7 Tough and tricky exponents and roots questions; 8 12 Easy Pieces (or not?); 9 Bakers' Dozen; 10 Algebra set. NEW!!!

DS: 1. DS tough questions; 2. DS tough questions part 2; 3. DS tough questions part 3; 4. DS Standard deviation; 5. Inequalities; 6. 700+ GMAT Data Sufficiency Questions With Explanations; 7 Tough and tricky exponents and roots questions; 8 The Discreet Charm of the DS ; 9 Devil's Dozen!!!; 10 Number Properties set. NEW!!!


What are GMAT Club Tests?
25 extra-hard Quant Tests

Find out what's new at GMAT Club - latest features and updates

Veritas Prep GMAT Instructor
User avatar
Joined: 16 Oct 2010
Posts: 3113
Location: Pune, India
Followers: 572

Kudos [?]: 2015 [0], given: 92

Re: If positive integer x is divided by 5, the result is p and [#permalink] New post 20 Apr 2012, 10:26
BN1989 wrote:
If positive integer x is divided by 5, the result is p and the remainder 3. If x is divided by 11, the remainder is 3 again, what is the remainder when p is divided by 11?

(A) 0
(B) 1
(C) 2
(D) 3
(E) 4

I had to plug in numbers, how can you solve this with the remainder formula?


If the remainder is same in both the cases,
x = 5p + 3
x = 11q + 3

then x = 55a + 3
(to understand this concept, check out http://www.veritasprep.com/blog/2011/05 ... emainders/)

Since 5p has 55 as a factor, p must be divisible by 11. So remainder is 0
_________________

Karishma
Veritas Prep | GMAT Instructor
My Blog

Save 10% on Veritas Prep GMAT Courses And Admissions Consulting
Enroll now. Pay later. Take advantage of Veritas Prep's flexible payment plan options.

Veritas Prep Reviews

Intern
Intern
Joined: 23 May 2012
Posts: 33
Followers: 0

Kudos [?]: 5 [0], given: 11

Re: If positive integer x is divided by 5, the result is p and [#permalink] New post 19 Oct 2012, 01:27
x=5p+3;
x=11q+3

So, 5p+3=11q+3..
5p=11q
p=11(q/5)

P should be a multiple of 11... & p divided by 11 should give R=0
Intern
Intern
Joined: 19 Apr 2012
Posts: 2
Concentration: Technology, General Management
GMAT Date: 04-26-2013
WE: Programming (Computer Software)
Followers: 0

Kudos [?]: 0 [0], given: 13

Re: If positive integer x is divided by 5, the result is p and [#permalink] New post 27 Nov 2012, 04:35
ENAFEX wrote:
Bunuel, I tried using this method below as described in

I got stuck. Please help

X=5P+3 , x can be 8 13 18 23...58
X=11Q+3, x can be 14,25,....58

To form the equation n=kx+r
n=55K+58

Not sure how to proceed.


Using the same approach, we know that at p=11 the value of X=58, for both the expressions. Hence p is a multiple of 11 so the remainder is 0.
Though this is still a more time consuming approach that the ones stated above.

Please correct me if I am wrong.

Nityam
Intern
Intern
Joined: 29 Jul 2012
Posts: 7
Location: United States
GMAT 1: 730 Q50 V39
GPA: 3.43
WE: Sales (Internet and New Media)
Followers: 0

Kudos [?]: 5 [0], given: 6

Re: If positive integer x is divided by 5, the result is p and [#permalink] New post 07 Mar 2013, 10:23
Hi I have a quick question on this problem. How are you getting to 55 in the combined equation? Why can't X be 3? If you divide 3 by both 5 and 11, the remainder is 3 so I'm not sure what I am missing. Thanks for any help you can give.
Veritas Prep GMAT Instructor
User avatar
Joined: 16 Oct 2010
Posts: 3113
Location: Pune, India
Followers: 572

Kudos [?]: 2015 [0], given: 92

Re: If positive integer x is divided by 5, the result is p and [#permalink] New post 07 Mar 2013, 21:02
aryah422 wrote:
Hi I have a quick question on this problem. How are you getting to 55 in the combined equation? Why can't X be 3? If you divide 3 by both 5 and 11, the remainder is 3 so I'm not sure what I am missing. Thanks for any help you can give.


I have discussed the general case there.

Given that:
x = 5p + 3
x = 11q + 3

We can say that x = 55a + 3
i.e. when we divide x by 55 (the LCM of 5 and 11), the remainder will be 3 in that case too.
To understand this fully, check out the link I gave in my previous post: http://www.veritasprep.com/blog/2011/05 ... emainders/

Sure, the number x can be 3 too. In that case p = 0, q = 0 and a = 0. When you divide p by 11, the remainder will be 0.
_________________

Karishma
Veritas Prep | GMAT Instructor
My Blog

Save 10% on Veritas Prep GMAT Courses And Admissions Consulting
Enroll now. Pay later. Take advantage of Veritas Prep's flexible payment plan options.

Veritas Prep Reviews

Re: If positive integer x is divided by 5, the result is p and   [#permalink] 07 Mar 2013, 21:02
    Similar topics Author Replies Last post
Similar
Topics:
New posts If a positive integer n is divided by 5, the remainder is 3. jimmyjamesdonkey 2 13 Feb 2008, 17:53
Popular new posts 7 EXPERTS_POSTS_IN_THIS_TOPIC When positive integer x is divided by 5, the remainder is 3; marcodonzelli 17 12 Mar 2008, 13:16
New posts 1 EXPERTS_POSTS_IN_THIS_TOPIC When the positive integer A is divided by 5 and 7, the mrinal2100 2 08 Nov 2010, 09:59
New posts 5 EXPERTS_POSTS_IN_THIS_TOPIC When positive integer x is divided by 5, the remainder is 3 shopaholic 1 02 Mar 2012, 10:39
New posts 1 EXPERTS_POSTS_IN_THIS_TOPIC If a is a positive integer and 81 divided by a results in a kashishh 6 16 Jun 2012, 14:48
Display posts from previous: Sort by

If positive integer x is divided by 5, the result is p and

  Question banks Downloads My Bookmarks Reviews  


GMAT Club MBA Forum Home| About| Privacy Policy| Terms and Conditions| GMAT Club Rules| Contact| Sitemap

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®.