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

It is currently 22 Oct 2014, 16:12

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

The tens digit of positive integer X is 3. Is the units

  Question banks Downloads My Bookmarks Reviews Important topics  
Author Message
TAGS:
Manager
Manager
avatar
Joined: 23 Mar 2008
Posts: 226
Followers: 1

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

The tens digit of positive integer X is 3. Is the units [#permalink] New post 04 Jun 2008, 12:27
1
This post was
BOOKMARKED
00:00
A
B
C
D
E

Difficulty:

(N/A)

Question Stats:

0% (00:00) correct 0% (00:00) wrong based on 0 sessions
The tens digit of positive integer X is 3. Is the units digit of X greater than 4?

1) the units digit if 2X is less than the units digit of X
2) the tens digit id 2X is7
Manager
Manager
avatar
Joined: 23 Mar 2008
Posts: 226
Followers: 1

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

Re: DS:tens digit [#permalink] New post 04 Jun 2008, 12:28
I made a typo in the 2nd condition. It should be

2) The tens digit of 2X is 7

Sorry
Senior Manager
Senior Manager
User avatar
Joined: 07 Jan 2008
Posts: 318
Location: Ann Arbor, Michigan
Schools: Ross Class of 2011
Followers: 6

Kudos [?]: 86 [0], given: 0

Re: DS:tens digit [#permalink] New post 04 Jun 2008, 12:38
D.

1 - tells us that the number has to be 36, 37, 38, or 39 all have units > 4. Simple to check 30 has same units, 31, 32, 33, 34 all have larger unit digits when multiplied by 2.

2 - tells us number must be 35 36 37 38 39 all lower would give us a 6 for a tens digit.

Last edited by lsuguy7 on 05 Jun 2008, 05:58, edited 1 time in total.
Current Student
avatar
Joined: 28 Dec 2004
Posts: 3403
Location: New York City
Schools: Wharton'11 HBS'12
Followers: 13

Kudos [?]: 164 [0], given: 2

Re: DS:tens digit [#permalink] New post 04 Jun 2008, 19:58
puma wrote:
The tens digit of positive integer X is 3. Is the units digit of X greater than 4?

1) the units digit if 2X is less than the units digit of X
2) the tens digit id 2X is7


i will go with B

1)
2*X unit digit is less than X..

suppose x=30 or 35.. in both cases unit digit of 2X is less than 2..however 5>4 and 0<4
Insuff

2)
2*3X=7Y

X has to be greater than 5..which is >4 Sufficient
Manager
Manager
avatar
Joined: 31 Jul 2006
Posts: 229
Followers: 1

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

Re: DS:tens digit [#permalink] New post 04 Jun 2008, 20:12
D for me as well.

In case for X=30 the units digit of 2X i.e 0 is not less than the units digit of X.
Director
Director
avatar
Joined: 01 May 2007
Posts: 795
Followers: 1

Kudos [?]: 79 [0], given: 0

Re: DS:tens digit [#permalink] New post 05 Jun 2008, 08:58
I'm saying D on this one folks. OA please?
CEO
CEO
User avatar
Joined: 29 Mar 2007
Posts: 2593
Followers: 16

Kudos [?]: 197 [0], given: 0

Re: DS:tens digit [#permalink] New post 05 Jun 2008, 09:18
puma wrote:
The tens digit of positive integer X is 3. Is the units digit of X greater than 4?

1) the units digit if 2X is less than the units digit of X
2) the tens digit id 2X is7


D

1: must be 5,6,7,8,9 to hold.

2: must be, 35, 6,7,8,9 to hold.
Current Student
avatar
Joined: 28 Dec 2004
Posts: 3403
Location: New York City
Schools: Wharton'11 HBS'12
Followers: 13

Kudos [?]: 164 [0], given: 2

Re: DS:tens digit [#permalink] New post 05 Jun 2008, 10:59
GMATBLACKBELT wrote:
puma wrote:
The tens digit of positive integer X is 3. Is the units digit of X greater than 4?

1) the units digit if 2X is less than the units digit of X
2) the tens digit id 2X is7


D

1: must be 5,6,7,8,9 to hold.

2: must be, 35, 6,7,8,9 to hold.

i dont get how A is sufficient..

supose X=30 or 35..

in both cases 2*X=60 or 70..so unit digit of 2X is 0..however unit digit of X is 5 or 0..so A is insuff..
Manager
Manager
avatar
Joined: 23 Mar 2008
Posts: 226
Followers: 1

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

Re: DS:tens digit [#permalink] New post 05 Jun 2008, 11:18
OA is D but I don't get why A is sufficient
Current Student
avatar
Joined: 28 Dec 2004
Posts: 3403
Location: New York City
Schools: Wharton'11 HBS'12
Followers: 13

Kudos [?]: 164 [0], given: 2

Re: DS:tens digit [#permalink] New post 05 Jun 2008, 12:06
i get it..

jeez..

suppose X=10X+y

then 2X=20X+2Y 2y<y... then y=5, 6,7, 8, 9...

A is sufficient..
VP
VP
User avatar
Joined: 18 May 2008
Posts: 1300
Followers: 13

Kudos [?]: 126 [0], given: 0

Re: DS:tens digit [#permalink] New post 05 Jun 2008, 23:50
Otherwise also, we cant take 30 because its not satisfying the first condition, so no confusion.
fresinha12 wrote:
GMATBLACKBELT wrote:
puma wrote:
The tens digit of positive integer X is 3. Is the units digit of X greater than 4?

1) the units digit if 2X is less than the units digit of X
2) the tens digit id 2X is7


D

1: must be 5,6,7,8,9 to hold.

2: must be, 35, 6,7,8,9 to hold.

i dont get how A is sufficient..

supose X=30 or 35..

in both cases 2*X=60 or 70..so unit digit of 2X is 0..however unit digit of X is 5 or 0..so A is insuff..
Re: DS:tens digit   [#permalink] 05 Jun 2008, 23:50
    Similar topics Author Replies Last post
Similar
Topics:
2 Experts publish their posts in the topic If the tens digit x and the units digit y of a positive eybrj2 9 07 Mar 2012, 14:32
3 If x is a positive integer, what is the units digit of 3x? siddhans 3 22 Jun 2011, 00:54
The tens digit of positive integer X is 3. Is the units mymba99 3 23 Apr 2008, 07:04
if the tens digit x and the units digit y of a positive lan583 6 18 Oct 2006, 15:07
If the tens digit x and the units digit y of a positive Avis 2 26 Feb 2006, 09:43
Display posts from previous: Sort by

The tens digit of positive integer X is 3. Is the units

  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®.