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

 It is currently 28 Apr 2015, 02:30

### 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

# p and q are integers. If p is divisible by 10^q and cannot

Author Message
TAGS:
Manager
Joined: 10 Feb 2011
Posts: 115
Followers: 1

Kudos [?]: 80 [0], given: 10

p and q are integers. If p is divisible by 10^q and cannot [#permalink]  10 Feb 2011, 15:05
17
This post was
BOOKMARKED
00:00

Difficulty:

45% (medium)

Question Stats:

59% (02:16) correct 41% (01:24) wrong based on 487 sessions
p and q are integers. If p is divisible by 10^q and cannot be divisible by 10^(q + 1), what is the value of q?

(1) p is divisible by 2^5, but is not divisible by 2^6.
(2) p is divisible by 5^6, but is not divisible by 5^7
[Reveal] Spoiler: OA

Last edited by Bunuel on 29 Oct 2013, 05:22, edited 1 time in total.
Veritas Prep GMAT Instructor
Joined: 16 Oct 2010
Posts: 5436
Location: Pune, India
Followers: 1325

Kudos [?]: 6722 [4] , given: 176

Re: p and q are integers. If p is divisible by 10q and canno [#permalink]  14 Jan 2014, 21:34
4
KUDOS
Expert's post
2
This post was
BOOKMARKED
Vidhi1 wrote:

How do we know the question is asking us to use the concept of trailing zeroes. I understand the concept but how do we know that we have to apply trailing zeroes concept.

Isn't that the core challenge of GMAT? The concepts tested are quite basic. Why then, does everyone not get Q50? Because you really need to understand them very well to be able to see which particular concept is used in a particular question.
Here, when you see

"If p is divisible by 10^q and cannot be divisible by 10^(q + 1)"
you should understand that p has q trailing 0s (that's how it is will be divisible by 10^q) but it does not have q+1 trailing 0s. This means it has exactly q trailing 0s.

If p has q trailing 0s, it must have at least q 2s and at least q 5s (but both 2s and 5s cannot be more than q)
Statement 1 tells you about the 2s but not about the 5s. Statement 2 tells you about the 5s but not about the 2s. Both statements together tell you that you can make five 0s. and hence q must be 5.
_________________

Karishma
Veritas Prep | GMAT Instructor
My Blog

Veritas Prep GMAT course is coming to India. Enroll in our weeklong Immersion Course that starts March 29!

Veritas Prep Reviews

Math Expert
Joined: 02 Sep 2009
Posts: 27123
Followers: 4199

Kudos [?]: 40541 [3] , given: 5540

Re: p and q are integers. If p is divisible by 10q and canno [#permalink]  10 Feb 2011, 15:43
3
KUDOS
Expert's post
5
This post was
BOOKMARKED
banksy wrote:
p and q are integers. If p is divisible by 10^q and cannot be divisible by 10^(q + 1), what is the value of q?
(1) p is divisible by 2^5, but is not divisible by 2^6.
(2) p is divisible by 5^6, but is not divisible by 5^7

p is divisible by 10^q and cannot be divisible by 10^(q + 1) means that # of trailing zeros of p is q (p ends with q zeros).

(1) p is divisible by 2^5, but is not divisible by 2^6 --> # of trailing zeros, q, is less than or equal to 5: $$q\leq{5}$$ (as for each trailing zero we need one 2 and one 5 in prime factorization of p then this statement says that there are enough 2-s for 5 zeros but we don't know how many 5-s are there). Not sufficient.

(2) p is divisible by 5^6, but is not divisible by 5^7 --> # of trailing zeros, q, is less than or equal to 6: $$q\leq{6}$$ (there are enough 5-s for 6 zeros but we don't know how many 2-s are there). Not sufficient.

(1)+(2) 2-s and 5-s are enough for 5 trailing zeros: $$q=5$$ (# of 2-s are limiting factor). Sufficient.

_________________
SVP
Joined: 06 Sep 2013
Posts: 2029
Concentration: Finance
GMAT 1: 710 Q48 V39
Followers: 24

Kudos [?]: 292 [1] , given: 354

Re: p and q are integers. If p is divisible by 10^q and cannot [#permalink]  05 Jan 2014, 05:58
1
KUDOS
banksy wrote:
p and q are integers. If p is divisible by 10^q and cannot be divisible by 10^(q + 1), what is the value of q?

(1) p is divisible by 2^5, but is not divisible by 2^6.
(2) p is divisible by 5^6, but is not divisible by 5^7

Yeah right on, what the question is really asking is what is the maximum number of trailing zeroes that P can have

With both statements together we get that the maximum number must be 5

Hence C is the correct answer

Hope it helps
Cheers!
J
Veritas Prep GMAT Instructor
Joined: 16 Oct 2010
Posts: 5436
Location: Pune, India
Followers: 1325

Kudos [?]: 6722 [1] , given: 176

Re: p and q are integers. If p is divisible by 10^q and cannot [#permalink]  14 Dec 2014, 03:09
1
KUDOS
Expert's post
sunilp wrote:
jlgdr wrote:
banksy wrote:
p and q are integers. If p is divisible by 10^q and cannot be divisible by 10^(q + 1), what is the value of q?

(1) p is divisible by 2^5, but is not divisible by 2^6.
(2) p is divisible by 5^6, but is not divisible by 5^7

Yeah right on, what the question is really asking is what is the maximum number of trailing zeroes that P can have

With both statements together we get that the maximum number must be 5

Hence C is the correct answer

Hope it helps
Cheers!
J

Hi, I did not get part where you said it is asking for maximum number of trailing zeros. Is it because of statement 1) ? thanks in advance.

What is the meaning of trailing zeroes?

102000 has 3 trailing zeroes i.e. 3 zeroes at the end.
1920040 has only 1 trailing zero.
Trailing zeroes means the number of zeroes at the end - after a non zero number.

Now think, 19200 = 192*100
So 19200 is divisible by 100 but not by 1000 or 10000 etc.
Since 19200 has 2 trailing zeroes, it will be divisible by 10^2 but not by 10^3 or 10^4 or 10^5 etc.

The question stem tells you that p is divisible by 10^q but not by 10^(q+1); this means that p has exactly q trailing zeroes.
For every 0 at the end, you need the number to be a multiple of 10 i.e. a 2 and a 5. Stmt 1 tells you that p has 5 2s and stmnt 2 tells you that p has 6 5s. Together, you can make only 5 10s. So q must be 5.
_________________

Karishma
Veritas Prep | GMAT Instructor
My Blog

Veritas Prep GMAT course is coming to India. Enroll in our weeklong Immersion Course that starts March 29!

Veritas Prep Reviews

Manager
Joined: 05 Nov 2012
Posts: 164
Followers: 1

Kudos [?]: 15 [0], given: 56

Re: p and q are integers. If p is divisible by 10q and canno [#permalink]  15 Nov 2012, 11:28
Bunuel wrote:
banksy wrote:
p and q are integers. If p is divisible by 10^q and cannot be divisible by 10^(q + 1), what is the value of q?
(1) p is divisible by 2^5, but is not divisible by 2^6.
(2) p is divisible by 5^6, but is not divisible by 5^7

p is divisible by 10^q and cannot be divisible by 10^(q + 1) means that # of trailing zeros of p is q (p ends with q zeros).

(1) p is divisible by 2^5, but is not divisible by 2^6 --> # of trailing zeros, q, is less than or equal to 5: $$q\leq{5}$$ (as for each trailing zero we need one 2 and one 5 in prime factorization of p then this statement says that there are enough 2-s for 5 zeros but we don't know how many 5-s are there). Not sufficient.

(2) p is divisible by 5^6, but is not divisible by 5^7 --> # of trailing zeros, q, is less than or equal to 6: $$q\leq{6}$$ (there are enough 5-s for 6 zeros but we don't know how many 2-s are there). Not sufficient.

(1)+(2) 2-s and 5-s are enough for 5 trailing zeros: $$q=5$$ (# of 2-s are limiting factor). Sufficient.

From condition 1 and condition 2 it we got $$q\leq{5}$$ and $$q\leq{6}$$ so possible cases can be $$q\leq{5}$$ so q can be anything 5,4,3,2,...... So both together aren't sufficient right?
Intern
Joined: 25 Nov 2013
Posts: 23
GMAT Date: 02-14-2014
GPA: 2.3
WE: Other (Internet and New Media)
Followers: 1

Kudos [?]: 3 [0], given: 11

Re: p and q are integers. If p is divisible by 10^q and cannot [#permalink]  14 Jan 2014, 21:05
jlgdr wrote:
banksy wrote:
p and q are integers. If p is divisible by 10^q and cannot be divisible by 10^(q + 1), what is the value of q?

(1) p is divisible by 2^5, but is not divisible by 2^6.
(2) p is divisible by 5^6, but is not divisible by 5^7

Yeah right on, what the question is really asking is what is the maximum number of trailing zeroes that P can have

With both statements together we get that the maximum number must be 5

Hence C is the correct answer

Hope it helps
Cheers!
J

can you please explain this question.
Intern
Joined: 25 Nov 2013
Posts: 23
GMAT Date: 02-14-2014
GPA: 2.3
WE: Other (Internet and New Media)
Followers: 1

Kudos [?]: 3 [0], given: 11

Re: p and q are integers. If p is divisible by 10q and canno [#permalink]  14 Jan 2014, 21:08
Bunuel wrote:
banksy wrote:
p and q are integers. If p is divisible by 10^q and cannot be divisible by 10^(q + 1), what is the value of q?
(1) p is divisible by 2^5, but is not divisible by 2^6.
(2) p is divisible by 5^6, but is not divisible by 5^7

p is divisible by 10^q and cannot be divisible by 10^(q + 1) means that # of trailing zeros of p is q (p ends with q zeros).

(1) p is divisible by 2^5, but is not divisible by 2^6 --> # of trailing zeros, q, is less than or equal to 5: $$q\leq{5}$$ (as for each trailing zero we need one 2 and one 5 in prime factorization of p then this statement says that there are enough 2-s for 5 zeros but we don't know how many 5-s are there). Not sufficient.

(2) p is divisible by 5^6, but is not divisible by 5^7 --> # of trailing zeros, q, is less than or equal to 6: $$q\leq{6}$$ (there are enough 5-s for 6 zeros but we don't know how many 2-s are there). Not sufficient.

(1)+(2) 2-s and 5-s are enough for 5 trailing zeros: $$q=5$$ (# of 2-s are limiting factor). Sufficient.

How do we know the question is asking us to use the concept of trailing zeroes. I understand the concept but how do we know that we have to apply trailing zeroes concept.
Intern
Joined: 04 Dec 2014
Posts: 1
GMAT Date: 04-30-2015
Followers: 0

Kudos [?]: 0 [0], given: 53

Re: p and q are integers. If p is divisible by 10^q and cannot [#permalink]  11 Dec 2014, 05:45
jlgdr wrote:
banksy wrote:
p and q are integers. If p is divisible by 10^q and cannot be divisible by 10^(q + 1), what is the value of q?

(1) p is divisible by 2^5, but is not divisible by 2^6.
(2) p is divisible by 5^6, but is not divisible by 5^7

Yeah right on, what the question is really asking is what is the maximum number of trailing zeroes that P can have

With both statements together we get that the maximum number must be 5

Hence C is the correct answer

Hope it helps
Cheers!
J

Hi, I did not get part where you said it is asking for maximum number of trailing zeros. Is it because of statement 1) ? thanks in advance.
Re: p and q are integers. If p is divisible by 10^q and cannot   [#permalink] 11 Dec 2014, 05:45
Similar topics Replies Last post
Similar
Topics:
2 If p is a positive integer and p^2 is divisible by 12 3 29 Dec 2014, 15:51
5 If P is divisible by 2, is Q + 5 an integer? (1) The median 8 02 Oct 2011, 14:45
If p is an integer, then p is divisible by how many positive 3 08 Feb 2009, 12:03
P and Q are integers. If P is divisible by 10^Q and cannot 1 27 Oct 2008, 01:19
2 If P, Q, R, and S are positive integers, and P/Q = R/S, is R divisible 12 02 Jul 2008, 21:20
Display posts from previous: Sort by