Find all School-related info fast with the new School-Specific MBA Forum
Learn more about the recent changes... close

It is currently 18 Jun 2013, 01:00
Customize  |  Hide

Search
Register
New posts
Unanswered

If x and y are positive integers, what is the remainder when

  Question banks Downloads My Bookmarks Reviews  
  Oldest Best Reply
Search for:
 
Print view
First unread post
Author Message
TAGS:
Manager
Manager
Joined: 06 Jul 2011
Posts: 216
Location: Accra, Ghana
Followers: 1

Kudos [?]: 15 [0], given: 39

GMAT Tests User
If x and y are positive integers, what is the remainder when [#permalink] New post 20 Mar 2012, 00:40
00:00

Question Stats:

75% (01:50) correct 24% (00:27) wrong based on 33 sessions
If x and y are positive integers, what is the remainder when 10^x +y is divided by 3?

(1) x=5
(2) y=2

I guessed on this question and I was lucky to get it right admittedly. I want to know the appropriate or possible appropriate method to use in solving this problem.
[Reveal] Spoiler: OA
2 KUDOS received
GMAT Club team member
User avatar
Joined: 02 Sep 2009
Posts: 12082
Followers: 1876

Kudos [?]: 10080 [2] , given: 956

GMAT Tests User CAT Tests
Top Member of the Month
Re: If x and y are positive integers... [#permalink] New post 20 Mar 2012, 00:51
2
This post received
KUDOS
If x and y are positive integers, what is the remainder when 10^x +y is divided by 3?

Since, the sum of the digits of 10^x is always 1 then the remainders when 10^x+y is divided by 3 is only dependant on the value of the number added to 10^x, so on y. If y is a multiple of 3 then 10^x+y will yield the remainder of 1 (since the sum of the digits of 10^x+y will be one more than a multiple of 3), if y is one more than a multiple of 3 then 10^x+y will yield the remainder of 2 and finally if y is two more than a multiple of 3 then 10^x+y will yield the remainder of 0,

(1) x=5. Not sufficient.
(2) y=2. Sufficient.

Answer: B.
_________________

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; 7. Remainders; 8. Overlapping Sets; 9. PDF of Math Book; 10. Remainders

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!!! ,11 Mixed Questions NEW!!!, 12 Fresh Meat 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!!!, 11 New DS set. NEW!!!


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

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

Intern
Intern
Joined: 14 Dec 2011
Posts: 6
Followers: 0

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

GMAT ToolKit User
Re: If x and y are positive integers, what is the remainder when [#permalink] New post 09 May 2012, 14:07
So the question should be ((10^x)+y)/3?

Image Posted from GMAT ToolKit
GMAT Club team member
User avatar
Joined: 02 Sep 2009
Posts: 12082
Followers: 1876

Kudos [?]: 10080 [0], given: 956

GMAT Tests User CAT Tests
Top Member of the Month
Re: If x and y are positive integers, what is the remainder when [#permalink] New post 09 May 2012, 14:57
nmartelo wrote:
So the question should be ((10^x)+y)/3?

Image Posted from GMAT ToolKit


Yes, it's: \frac{10^x+y}{3}.
_________________

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; 7. Remainders; 8. Overlapping Sets; 9. PDF of Math Book; 10. Remainders

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!!! ,11 Mixed Questions NEW!!!, 12 Fresh Meat 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!!!, 11 New DS set. NEW!!!


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

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

1 KUDOS received
Manager
Manager
User avatar
Joined: 13 Feb 2012
Posts: 149
Location: Italy
Concentration: General Management, Entrepreneurship
GMAT 1: 560 Q36 V34
GPA: 3.1
WE: Sales (Transportation)
Followers: 4

Kudos [?]: -1 [1] , given: 85

Re: If x and y are positive integers, what is the remainder when [#permalink] New post 05 Sep 2012, 03:17
1
This post received
KUDOS
The OG explanations sometimes really baffle me; I reached the solution simply by realizing that it did not matter what power the 10 was to be elevated to, and to know the value of y was sufficient; just like Bunuel explained above. The OG explanation should not be the primary route, in my opinion.
_________________

"The Burnout" - My Debrief

Kudos if I helped you ;)


Andy

Re: If x and y are positive integers, what is the remainder when   [#permalink] 05 Sep 2012, 03:17
    Similar topics Author Replies Last post
Similar
Topics:
 New posts If x and y are positive integers, what is the remainder when pb_india 7 10 Jan 2005, 12:26
New posts 2 If x and y are positive integers, what is the remainder when xALIx 3 01 Jul 2008, 15:57
New posts If x and y are positive integers, what is the remainder when jjhko 1 19 Jul 2008, 15:41
New posts 2 Experts publish their posts in the topic If x and y are positive integer, what is the remainder when gmat620 4 02 Nov 2009, 07:15
Popular new posts 5 Experts publish their posts in the topic If x and y are positive integers, what is the remainder when nusmavrik 15 04 Aug 2010, 15:17
Display posts from previous: Sort by

If x and y are positive integers, what is the remainder when

  Question banks Downloads My Bookmarks Reviews  
Print view
First unread post

Moderators: VeritasPrepKarishma, Bunuel, IanStewart

Search for:


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®.

Main navigation

GMAT Resources

Partners

MBA Resources

www.gmac.com|www.mba.com