Last visit was: 26 Apr 2024, 04:48 It is currently 26 Apr 2024, 04:48

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
SORT BY:
Date
Tags:
Show Tags
Hide Tags
Math Expert
Joined: 02 Sep 2009
Posts: 92929
Own Kudos [?]: 619145 [4]
Given Kudos: 81609
Send PM
Manager
Manager
Joined: 24 Oct 2016
Posts: 196
Own Kudos [?]: 63 [0]
Given Kudos: 89
Location: India
Concentration: Finance, International Business
Schools: IIMB
GMAT 1: 550 Q42 V28
GPA: 3.96
WE:Human Resources (Retail Banking)
Send PM
Board of Directors
Joined: 11 Jun 2011
Status:QA & VA Forum Moderator
Posts: 6072
Own Kudos [?]: 4690 [0]
Given Kudos: 463
Location: India
GPA: 3.5
WE:Business Development (Commercial Banking)
Send PM
avatar
Manager
Manager
Joined: 06 Jun 2016
Posts: 233
Own Kudos [?]: 110 [0]
Given Kudos: 212
Location: India
Concentration: Operations, Strategy
Schools: ISB '18 (D)
GMAT 1: 600 Q49 V23
GMAT 2: 680 Q49 V34
GPA: 3.9
Send PM
Re: If x and y are positive integers and 4500x = y^3, what is the minimum [#permalink]
Bunuel wrote:
If x and y are positive integers and 4500x = y^3, what is the minimum possible value of x?

A. 5
B. 6
C. 12
D. 30
E. 90


4500= (2^2)*(3^2)*(5^3)
4500x= y^3 ==> x=2*3=6
B
Target Test Prep Representative
Joined: 14 Oct 2015
Status:Founder & CEO
Affiliations: Target Test Prep
Posts: 18761
Own Kudos [?]: 22055 [0]
Given Kudos: 283
Location: United States (CA)
Send PM
Re: If x and y are positive integers and 4500x = y^3, what is the minimum [#permalink]
Expert Reply
Bunuel wrote:
If x and y are positive integers and 4500x = y^3, what is the minimum possible value of x?

A. 5
B. 6
C. 12
D. 30
E. 90


We are given that 4500x = y^3, which means that 4500x is a perfect cube. We must remember that all perfect cubes break down to unique prime factors, each of which has an exponent that is a multiple of 3. So, let’s break down 4500 into its prime factors to determine the minimum value of x.

4500 = 45 x 100 = 5 x 9 x 10 x 10 = 5 x 3 x 3 x 2 x 5 x 2 x 5 = 2^2 x 3^2 x 5^3

In order to make 4500x a perfect cube, the smallest value of x is 2^1 x 3^1, so that 4500x = (2^2 x 3^2 x 5^3) x (2^1 x 3^1) = 2^3 x 3^3 x 5^3, which is a perfect cube.

Thus, x = 2^1 x 3^1 = 6.

Answer: B
Manager
Manager
Joined: 05 Dec 2016
Posts: 194
Own Kudos [?]: 88 [0]
Given Kudos: 49
Concentration: Strategy, Finance
GMAT 1: 620 Q46 V29
Send PM
Re: If x and y are positive integers and 4500x = y^3, what is the minimum [#permalink]
To answer the question correctly it is needed to understand that if y^3=4500x, than root extraction is possible from 4500x.the
First, we need to do prime factorization of 4500, to discover prime factors and its powers.
So, prime factorization of 4500 = 2^2 * 3^2 * 5^3.
5^3 can be easily extracted from the root, but we still have 2^2 and 3^2, it is obvioud that in order to make it possible to extract from root^3 we need to add 1 power to each of factors 3 & 2, after addition of 3^1*2^1, root^3 extraction has become possible. 3*2 = 6, thus correct answer is B
User avatar
Non-Human User
Joined: 09 Sep 2013
Posts: 32684
Own Kudos [?]: 822 [0]
Given Kudos: 0
Send PM
Re: If x and y are positive integers and 4500x = y^3, what is the minimum [#permalink]
Hello from the GMAT Club BumpBot!

Thanks to another GMAT Club member, I have just discovered this valuable topic, yet it had no discussion for over a year. I am now bumping it up - doing my job. I think you may find it valuable (esp those replies with Kudos).

Want to see all other topics I dig out? Follow me (click follow button on profile). You will receive a summary of all topics I bump in your profile area as well as via email.
User avatar
Non-Human User
Joined: 09 Sep 2013
Posts: 32684
Own Kudos [?]: 822 [0]
Given Kudos: 0
Send PM
Re: If x and y are positive integers 4500x = y3, what is the [#permalink]
Hello from the GMAT Club BumpBot!

Thanks to another GMAT Club member, I have just discovered this valuable topic, yet it had no discussion for over a year. I am now bumping it up - doing my job. I think you may find it valuable (esp those replies with Kudos).

Want to see all other topics I dig out? Follow me (click follow button on profile). You will receive a summary of all topics I bump in your profile area as well as via email.
GMAT Club Bot
Re: If x and y are positive integers 4500x = y3, what is the [#permalink]
Moderators:
Math Expert
92929 posts
Senior Moderator - Masters Forum
3137 posts

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