GMAT Question of the Day - Daily to your Mailbox; hard ones only

 It is currently 18 Oct 2019, 22:32 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

Not interested in getting valuable practice questions and articles delivered to your email? No problem, unsubscribe here.  A perfect square is a positive integer which when square rooted result

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

Hide Tags

Math Expert V
Joined: 02 Sep 2009
Posts: 58453
A perfect square is a positive integer which when square rooted result  [#permalink]

Show Tags 00:00

Difficulty:   45% (medium)

Question Stats: 63% (01:19) correct 37% (01:27) wrong based on 78 sessions

HideShow timer Statistics

A perfect square is a positive integer which when square rooted results in an integer. If $$N = 3^4*5^3*7$$, then what is the biggest perfect square that is a factor of N ?

(A) 3^2
(B) 5^2
(C) 9^2
(D) (9*5)^2
(E) (3*5*7)^2

_________________
GMAT Club Legend  D
Joined: 18 Aug 2017
Posts: 5020
Location: India
Concentration: Sustainability, Marketing
GPA: 4
WE: Marketing (Energy and Utilities)
A perfect square is a positive integer which when square rooted result  [#permalink]

Show Tags

Bunuel wrote:
A perfect square is a positive integer which when square rooted results in an integer. If $$N = 3^4*5^3*7$$, then what is the biggest perfect square that is a factor of N ?

(A) 3^2
(B) 5^2
(C) 9^2
(D) (9*5)^2
(E) (3*5*7)^2

$$N = 3^4*5^3*7$$
perfect squre = 3^2*5*√35 ; 45
so biggest factor would be (9*5)^2
IMO D

Originally posted by Archit3110 on 10 Apr 2019, 03:25.
Last edited by Archit3110 on 11 Apr 2019, 00:10, edited 1 time in total.
Intern  B
Joined: 06 Apr 2019
Posts: 9
A perfect square is a positive integer which when square rooted result  [#permalink]

Show Tags

As we can see Square root of 3^4*5^2 will be 3^2*5 or 9*5
so for N=3^4∗5^3∗7, (9*5)^2 will be biggest perfect square factor.
D
Target Test Prep Representative D
Status: Founder & CEO
Affiliations: Target Test Prep
Joined: 14 Oct 2015
Posts: 8109
Location: United States (CA)
Re: A perfect square is a positive integer which when square rooted result  [#permalink]

Show Tags

Bunuel wrote:
A perfect square is a positive integer which when square rooted results in an integer. If $$N = 3^4*5^3*7$$, then what is the biggest perfect square that is a factor of N ?

(A) 3^2
(B) 5^2
(C) 9^2
(D) (9*5)^2
(E) (3*5*7)^2

Recall that a perfect square always has prime factors whose exponents are even numbers. So the perfect squares that are factors of N are 3^4 and 5^2. Therefore, the biggest perfect square that is a factor of N is 3^4 x 5^2 = (3^2 x 5)^2 = (9 x 5)^2.

_________________

Scott Woodbury-Stewart

Founder and CEO

Scott@TargetTestPrep.com

See why Target Test Prep is the top rated GMAT quant course on GMAT Club. Read Our Reviews

If you find one of my posts helpful, please take a moment to click on the "Kudos" button. Re: A perfect square is a positive integer which when square rooted result   [#permalink] 13 Apr 2019, 18:37
Display posts from previous: Sort by

A perfect square is a positive integer which when square rooted result

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

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