It is currently 15 Dec 2017, 21:44

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.

Close

Request Expert Reply

Confirm Cancel

Events & Promotions

Events & Promotions in June
Open Detailed Calendar

Is √p a non-integer? (1) p = r × 10 r, where r is a positive odd in

  new topic post reply Question banks Downloads My Bookmarks Reviews Important topics  
Author Message
TAGS:

Hide Tags

Senior SC Moderator
User avatar
D
Joined: 14 Nov 2016
Posts: 1254

Kudos [?]: 1366 [0], given: 440

Location: Malaysia
GMAT ToolKit User Premium Member CAT Tests
Is √p a non-integer? (1) p = r × 10 r, where r is a positive odd in [#permalink]

Show Tags

New post 23 Mar 2017, 17:11
1
This post was
BOOKMARKED
00:00
A
B
C
D
E

Difficulty:

  35% (medium)

Question Stats:

64% (01:01) correct 36% (01:04) wrong based on 105 sessions

HideShow timer Statistics

Is \(√p\) a non-integer?

(1) \(p = r × 10^r\), where r is a positive odd integer.
(2) \(p = 9 × 10^s\), where s is a positive integer.
[Reveal] Spoiler: OA

_________________

"Be challenged at EVERY MOMENT."

“Strength doesn’t come from what you can do. It comes from overcoming the things you once thought you couldn’t.”

"Each stage of the journey is crucial to attaining new heights of knowledge."

Rules for posting in verbal forum | Please DO NOT post short answer in your post!

Kudos [?]: 1366 [0], given: 440

Director
Director
User avatar
P
Joined: 05 Mar 2015
Posts: 966

Kudos [?]: 301 [0], given: 41

Re: Is √p a non-integer? (1) p = r × 10 r, where r is a positive odd in [#permalink]

Show Tags

New post 23 Mar 2017, 18:10
avinsethi wrote:
A?

Sent from my ONEPLUS A3003 using GMAT Club Forum mobile app


Yes its A...

(1) 10^odd integer is never a square .
HEre r is odd integer.

suff.

(2) we dont have enough info of s (even /odd).
if s=even then YES
if s=odd then NO
insuff

Ans A

Kudos [?]: 301 [0], given: 41

VP
VP
avatar
P
Joined: 26 Mar 2013
Posts: 1296

Kudos [?]: 302 [0], given: 166

Reviews Badge CAT Tests
Is √p a non-integer? (1) p = r × 10 r, where r is a positive odd in [#permalink]

Show Tags

New post 23 Mar 2017, 18:20
Is \(√p\) a non-integer?

(1) \(p = r × 10^r\), where r is a positive odd integer.

Let r= 1..........\(√10\)...........Answer is yes

Let r= 3..........\(√10^3\)...........Answer is yes

Any ODD power will yield always NON-Integer number

Sufficient

(2) \(p = 9 × 10^s\), where s is a positive integer.

Let s= 1..........\(√9*10\)...........Answer is yes

Let s= 2..........\(√9*10^2\)...........Answer is No

Insufficient

Answer A

Kudos [?]: 302 [0], given: 166

Director
Director
avatar
S
Joined: 12 Nov 2016
Posts: 792

Kudos [?]: 39 [0], given: 166

Re: Is √p a non-integer? (1) p = r × 10 r, where r is a positive odd in [#permalink]

Show Tags

New post 25 Sep 2017, 17:17
hazelnut wrote:
Is \(√p\) a non-integer?

(1) \(p = r × 10^r\), where r is a positive odd integer.
(2) \(p = 9 × 10^s\), where s is a positive integer.


Statement 1

In order for the square root of p to be an integer there must be an even number of exponents in the factors of p squared- for example

100 = 5^2 * 2^2
64= 2^6
9= 3^2


suff

Statement 2

Too many possibilities- it is not known whether or not s is odd

insuff

A

Kudos [?]: 39 [0], given: 166

Senior Manager
Senior Manager
avatar
S
Joined: 15 Jan 2017
Posts: 343

Kudos [?]: 5 [0], given: 775

CAT Tests
Re: Is √p a non-integer? (1) p = r × 10 r, where r is a positive odd in [#permalink]

Show Tags

New post 04 Nov 2017, 11:06
1) p = r x10 to power r
--> 1 x 10^1 = 10 --> _/10 is not integer
--> 3 x 10^ 3 = _/3 *1000 not integer
--> 5 x 10^5 = _/5 *100000 not integer
Suff

2) p= 9 x 10^s --> _/9 *10 is s = 1 --> 3_/10 is not Int
is s = 2 then p = 9 *100 --> under root = 3 *10 = integer
Hence, not suff

Ans A

Kudos [?]: 5 [0], given: 775

Intern
Intern
avatar
B
Joined: 03 May 2017
Posts: 8

Kudos [?]: 0 [0], given: 5

Location: United States
Concentration: Technology, Entrepreneurship
GPA: 3.86
Is √p a non-integer? (1) p = r × 10 r, where r is a positive odd in [#permalink]

Show Tags

New post 05 Nov 2017, 11:47
hazelnut wrote:
Is \(√p\) a non-integer?

(1) \(p = r × 10^r\), where r is a positive odd integer.
(2) \(p = 9 × 10^s\), where s is a positive integer.


2 is easier to evaluate, let's start there:
2) \(p = 9 × 10^s\), if s is odd, then \(\sqrt{p}\) is a non-integer.
If s is even, then \(\sqrt{p} = \sqrt{(3*3)*(10*10)^\frac{s}{2}} = 3*(10)^\frac{s}{2}\), an integer.
NS


1) \(\sqrt{p} =\sqrt{r * 10^r} = \sqrt{r * 10 * 10^{(r-1)}}\)
because r is odd, we know \(r-1\) is even. Therefore \(\sqrt{10^{(r-1)}}\) is an integer, which leaves us with:
\(\sqrt{r * 10} = \sqrt{r * 2 * 5}\)
because r is odd, there is no way to get the second power of 2 under the radical. The result will always be something\(*\sqrt{2}\), a non-integer.

The answer is A.

Kudos [?]: 0 [0], given: 5

Is √p a non-integer? (1) p = r × 10 r, where r is a positive odd in   [#permalink] 05 Nov 2017, 11:47
Display posts from previous: Sort by

Is √p a non-integer? (1) p = r × 10 r, where r is a positive odd in

  new topic post reply Question banks Downloads My Bookmarks Reviews Important topics  


cron

GMAT Club MBA Forum Home| About| Terms and Conditions| GMAT Club Rules| Contact| Sitemap

Powered by phpBB © phpBB Group | Emoji artwork provided by EmojiOne

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®.