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

 It is currently 06 May 2015, 11:49

### 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

# If k is a two digit positive integer, what is the value of

Author Message
TAGS:
GMAT Instructor
Joined: 04 Jul 2006
Posts: 1269
Followers: 23

Kudos [?]: 158 [0], given: 0

If k is a two digit positive integer, what is the value of [#permalink]  27 Oct 2006, 00:31
1
This post was
BOOKMARKED
00:00

Difficulty:

(N/A)

Question Stats:

0% (00:00) correct 0% (00:00) wrong based on 0 sessions
If k is a two digit positive integer, what is the value of k?

(1) There is exactly 1 three digit integer that is a multiple of both 140 and 21k.
(2) Each prime factor of k is a factor of 140.
Intern
Joined: 04 Sep 2006
Posts: 11
Followers: 0

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

C

Stem: k has to be 2 digit

Stat1: One 3 digit number multiple of both 140 and 21k

For 140: You can multiply 140 from 1 to 7 and still have 3 digit number
factors of 140 are 2,2,5,7

For 21k: factors are 3,7,k

It means: 140's multiple has to have 3 as a factor...that gives two choices multiply by 3 or 6....420 or 840....both of them have k=20 or 40....Insuff

Stat2:Each prime factor of k is a factor of 140
means k=10,14,20,28,35,70......Insuff

Combining...

k=20...Suff
Intern
Joined: 08 Jul 2006
Posts: 11
Followers: 0

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

State 1)
The 3 digit number, let say Y, can be:
140 - 280 - 420 - 560 - 700 - 840 - 980
We can write 21k like 3*7*k. That means that the 3 digit number Y, must be divided at least by 3 and 7
From the group, there are only two possibilities : 420 and 840
Dividing 420 and 840 by 21 (3*7), we can obtain the value of k
K can be 20 or 40
INSUFF

State 2)
The prime factors of 140 are 2,5 and 7
The 2 digits possibilities with those factors are : 4,10,14,20,28,35,70
K can be anyone from this group
INSUFF

State 1+2)
From 1) : K can be 20 or 40
From 2) Only 20 is one of the alternatives
SUFFICIENT

SVP
Joined: 24 Aug 2006
Posts: 2134
Followers: 3

Kudos [?]: 98 [0], given: 0

Re: DS: Value of k [#permalink]  27 Oct 2006, 07:06
kevincan wrote:
If k is a two digit positive integer, what is the value of k?

(1) There is exactly 1 three digit integer that is a multiple of both 140 and 21k.

I like A.

Strategy-wise, this is a tough question, therefore, answers C and E are doubtful.

If 140 and 21k has exactly one 3 digit common multiple, then K is solvable.

Find all 3 digit multiples of 140

140, 280, 420, 560, 700, 840, 980

The only ones divisible by 21 are 420 and 840.

If k=20, then there are TWO 3 digit multiples of 140 and 21k (420 and 840).
If k=40, then there is only ONE 3 digit multiple of 140 and 21k (840)

Therefore K=40.

SUFF

------------------------

kevincan wrote:
(2) Each prime factor of k is a factor of 140.

The prime factors of 140 = 2, 2, 5, 7

Therefore, the prime factors of K=any combination of above prime factors.

K=10, 20, 28, 35, 70 etc etc. Too many options,
INSUFF
Manager
Joined: 31 Aug 2006
Posts: 213
Followers: 1

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

I beleive (A).

Stat (1) - SUFF
420 and 840 are the only three digit numbers which can be a multiple of 140 and 21*k.
Again for k=8 we get only "1 three digit integer" as 840

Stat(2) - INSUFF
Because k=2 or k=7 etc..
Current Student
Joined: 28 Dec 2004
Posts: 3391
Location: New York City
Schools: Wharton'11 HBS'12
Followers: 13

Kudos [?]: 181 [0], given: 2

Re: DS: Value of k [#permalink]  30 Oct 2006, 08:09
is the stem sayin 21*K or 21k; where k is a 2 digit number..in the later case...its not possible..

kevincan wrote:
If k is a two digit positive integer, what is the value of k?

(1) There is exactly 1 three digit integer that is a multiple of both 140 and 21k.
(2) Each prime factor of k is a factor of 140.
VP
Joined: 28 Mar 2006
Posts: 1384
Followers: 2

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

Re: DS: Value of k [#permalink]  30 Oct 2006, 17:29
kevincan wrote:
If k is a two digit positive integer, what is the value of k?

(1) There is exactly 1 three digit integer that is a multiple of both 140 and 21k.
(2) Each prime factor of k is a factor of 140.

It should be E

From 1) k can be 20 or 40

From (2) each prime factor of k is a factor of 140 NOT SUFF

Combining both both 20 and 40 prime factors are also factor od 140

So INSUFF
Re: DS: Value of k   [#permalink] 30 Oct 2006, 17:29
Similar topics Replies Last post
Similar
Topics:
6 what is the value of the two-digit positive integer n? 2 01 Dec 2014, 18:04
15 What is the value of the two-digit positive integer n? 6 16 Mar 2013, 13:04
If N is a two-digit positive integer, what is the value of 2 17 Jan 2011, 23:02
If PQ is a two digit positive integer, what is the value of 4 03 Nov 2007, 13:44
Display posts from previous: Sort by