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

It is currently 24 Oct 2014, 16:58

Close

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
Your Progress

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

Not interested in getting valuable practice questions and articles delivered to your email? No problem, unsubscribe here.

Events & Promotions

Events & Promotions in June
Open Detailed Calendar

If the units digit of the three-digit positive integer k is

  Question banks Downloads My Bookmarks Reviews Important topics  
Author Message
TAGS:
Manager
Manager
avatar
Joined: 02 Oct 2009
Posts: 93
Followers: 1

Kudos [?]: 6 [0], given: 2

If the units digit of the three-digit positive integer k is [#permalink] New post 17 Oct 2009, 19:28
1
This post was
BOOKMARKED
00:00
A
B
C
D
E

Difficulty:

  55% (hard)

Question Stats:

59% (02:12) correct 41% (01:23) wrong based on 145 sessions
If the units digit of the three-digit positive integer k is nonzero, what is the tens digit of k?

(1) The tens digit of k + 9 is 3.
(2) The tens digit of k + 4 is 2.
[Reveal] Spoiler: OA

Last edited by Bunuel on 23 May 2013, 03:51, edited 2 times in total.
Added the OA
1 KUDOS received
Manager
Manager
avatar
Joined: 11 Sep 2009
Posts: 129
Followers: 4

Kudos [?]: 180 [1] , given: 6

Re: DS number problem [#permalink] New post 17 Oct 2009, 19:44
1
This post received
KUDOS
The answer is A.

We know the following:

(a) k is a 3 digit positive integer
(b) The units digit of k is NOT zero

Statement 1: The tens digit of k + 9 is 3.

If k + 9 has a tens digit of X, the only way k has a tens digit of X as well is if the units digit of k is zero. Since we know the units digit of k is NOT zero, the tens digit of k MUST be 2.

Sufficient.

Statement 2: Then tens digit of k+4 is 2.

The tens digit of k can be 1 or 2. Insufficient.
Manager
Manager
avatar
Joined: 12 Oct 2009
Posts: 115
Followers: 2

Kudos [?]: 23 [0], given: 3

Re: DS number problem [#permalink] New post 18 Oct 2009, 00:01
will go with A

Lets consider k = 100x + 10y +z where z is units digit and y is tens digit
we know z is not equal to zero i.e z is b/w 1 and 9 inclusive
we need to find y

1. tens digit of k + 9 is 3 ie z+9 will give the new value of y
since z+9 gives y = 3 then y=2 before 9 is added to z (z is 1 to 9 inclusive) . hence suff

2. tens digit of k + 4 is 2
now if z= 6 or 7 or 8 or 9 then on adding 4, y value will get incremented by 1 so value of y (before adding 4 ) is 1
but if z is b/w 1 to 5 (inclusive) then value of y will not change and y will be equal to 2
hence insuff
Director
Director
User avatar
Status: GMAT Learner
Joined: 14 Jul 2010
Posts: 650
Followers: 34

Kudos [?]: 254 [0], given: 32

Re: If the units digit of the three-digit positive integer k is [#permalink] New post 29 Jan 2012, 06:32
Let k =abc (c ≠ 0) question is b= ?

(1) As c ≠ 0, so b+9 means k+9, if k+9 then b = 3. it is possible if b = 2 only
[123 + 9 = 132, 122+9= 131]
sufficient
(2) k+4 = b = 2, 118+4 = 122, b = 1
123 = 127 b= 2
Insufficient.
Ans. A
_________________

I am student of everyone-baten
Collections:-
PSof OG solved by GC members: http://gmatclub.com/forum/collection-ps-with-solution-from-gmatclub-110005.html
DS of OG solved by GC members: http://gmatclub.com/forum/collection-ds-with-solution-from-gmatclub-110004.html
100 GMAT PREP Quantitative collection http://gmatclub.com/forum/gmat-prep-problem-collections-114358.html
Collections of work/rate problems with solutions http://gmatclub.com/forum/collections-of-work-rate-problem-with-solutions-118919.html
Mixture problems in a file with best solutions: http://gmatclub.com/forum/mixture-problems-with-best-and-easy-solutions-all-together-124644.html

Expert Post
1 KUDOS received
Math Expert
User avatar
Joined: 02 Sep 2009
Posts: 23409
Followers: 3613

Kudos [?]: 28921 [1] , given: 2871

Re: If the units digit of the three-digit positive integer k is [#permalink] New post 29 Jan 2012, 06:40
1
This post received
KUDOS
Expert's post
2
This post was
BOOKMARKED
If the units digit of the three-digit positive integer k is nonzero, what is the tens digit of k?

Given that: k=abc and c is nonzero. Question b=?

(1) The tens digit of k + 9 is 3:
abc
+9
---
a3x

Tens digit of k+9, which is 3, gains 1 unit from c+9 (as c is not zero), hence b+1=3 --> b=2. Sufficient.

(2) The tens digit of k + 4 is 2
abc
+4
---
a2x

Tens digit of k + 4, which is 2, may or may not gain 1 unit from c+4, hence either b+1=2 or b+0=2. Two different values for b. Not sufficient.

Answer: A.

Hope it's clear.
_________________

NEW TO MATH FORUM? PLEASE READ THIS: ALL YOU NEED FOR QUANT!!!

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; 11. GMAT Prep Software Analysis NEW!!!; 12. SEVEN SAMURAI OF 2012 (BEST DISCUSSIONS) NEW!!!; 12. Tricky questions from previous years. NEW!!!;

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. ,11 Mixed Questions, 12 Fresh Meat

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., 11 New DS set.


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

Get the best GMAT Prep Resources with GMAT Club Premium Membership

Expert Post
Math Expert
User avatar
Joined: 02 Sep 2009
Posts: 23409
Followers: 3613

Kudos [?]: 28921 [0], given: 2871

Re: If the units digit of the three-digit positive integer k is [#permalink] New post 22 Aug 2013, 04:20
Expert's post
CEO
CEO
User avatar
Joined: 09 Sep 2013
Posts: 2858
Followers: 207

Kudos [?]: 43 [0], given: 0

Premium Member
Re: If the units digit of the three-digit positive integer k is [#permalink] New post 25 Sep 2014, 05:29
Hello from the GMAT Club BumpBot!

Thanks to another GMAT Club member, I have just discovered this valuable topic, yet it had no discussion for over a year. I am now bumping it up - doing my job. I think you may find it valuable (esp those replies with Kudos).

Want to see all other topics I dig out? Follow me (click follow button on profile). You will receive a summary of all topics I bump in your profile area as well as via email.
_________________

GMAT Books | GMAT Club Tests | Best Prices on GMAT Courses | GMAT Mobile App | Math Resources | Verbal Resources

Re: If the units digit of the three-digit positive integer k is   [#permalink] 25 Sep 2014, 05:29
    Similar topics Author Replies Last post
Similar
Topics:
If the units digit of the three-digit positive integer k is bhaarat 4 20 May 2007, 19:42
If the units digit of the three-digit positive integer k shinewine 3 26 Aug 2006, 06:45
If the units digit of the three-digit positive integer k is mbassmbass04 1 01 Oct 2005, 15:28
If the units digit of the three-digit positive integer k is pb_india 3 18 Jan 2005, 19:44
If the units digit of the three-digit positive integer k is NEWKID 2 06 Nov 2004, 09:29
Display posts from previous: Sort by

If the units digit of the three-digit positive integer k is

  Question banks Downloads My Bookmarks Reviews Important topics  


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®.