Author 
Message 
TAGS:

Hide Tags

Manager
Joined: 28 Aug 2008
Posts: 93

If x and y are positive integers and x^3*y^4 = 2000 what is
[#permalink]
Show Tags
11 Sep 2008, 14:36
Question Stats:
86% (01:27) correct 14% (01:36) wrong based on 675 sessions
HideShow timer Statistics
If x and y are positive integers, and x^3*y^4 = 2,000, which of the following is the value of xy? A. 2 B. 4 C. 8 D. 10 E. 20
Official Answer and Stats are available only to registered users. Register/ Login.




Intern
Joined: 10 Feb 2014
Posts: 16
Location: United States
Concentration: Strategy, Real Estate
GMAT Date: 06202014
GPA: 3.04
WE: Business Development (NonProfit and Government)

Re: If x and y are positive integers and x^3*y^4 = 2000 what is
[#permalink]
Show Tags
08 Apr 2014, 19:52
for this problem, i factored 2000 > 2, 2, 2, 2, 5, 5, 5... or (5*3)(2*4).
based on the factoring, x = 5 and y = 2... so xy = (5)(2) = 10
the correct answer is d.




SVP
Joined: 07 Nov 2007
Posts: 1687
Location: New York

Re: PS.. More Exp
[#permalink]
Show Tags
11 Sep 2008, 14:51
IgnitedMind wrote: If x and y are positive integers and x^3*y^4 = 2000 what is the value of xy?
2
4
8
10
20 10 \((5*2)^{3}*2=2000\) D
_________________
Your attitude determines your altitude Smiling wins more friends than frowning



Intern
Joined: 14 Sep 2003
Posts: 42
Location: california

Re: intergers
[#permalink]
Show Tags
09 Nov 2008, 21:42
pardon me asking...is the question stem valid asis? I am finding it hard to deduce a set of +ve integer values for x and y satisfying the below equation x^3y^4 = 2000 even if you take x=2 and y =1, the lowest possible values, it is still <> 2000.
_________________
excellence is the gradual result of always striving to do better



VP
Joined: 17 Jun 2008
Posts: 1443

Re: intergers
[#permalink]
Show Tags
10 Nov 2008, 07:22
2000 = 5^3*2^4 Hence, xy = 10



Manager
Joined: 30 Sep 2008
Posts: 111

Re: intergers
[#permalink]
Show Tags
10 Nov 2008, 08:13
scthakur wrote: 2000 = 5^3*2^4 Hence, xy = 10 how long did it take you to figure out x and y? I looked at your answer before solving this so just want to estimate which method is better when taking the test. x^3y^4 = (xy)^3 * y = 2000 a. if xy = 2 => 2^3 = 8, can't find y b. xy = 4 (same as above) c. xy = 8, 8^3 = 512; 2000/512 is not integer d. xy = 10, 10^3 = 1000, y = 2000/1000 = 2 e. xy = 20, 20^3 = 8000 > 2000 so the answer is D



VP
Joined: 17 Jun 2008
Posts: 1443

Re: intergers
[#permalink]
Show Tags
10 Nov 2008, 10:15
Actually, I had seen this problem before. Haaving said that, in such types of problems, it is better to break the big number into squares, cubes, etc. of smaller numbers.



Retired Moderator
Joined: 05 Jul 2006
Posts: 1727

Re: intergers
[#permalink]
Show Tags
10 Nov 2008, 11:49
[quote="Jcpenny"]If x and y are positive integers, and x^3y^4 = 2,000, which of the following is the value of xy?
A. 2 B. 4 C. 8 D. 10 E. 20
1000*2 = 10^3*2 = 5^3*2^4 thus xy = 10...D



Manager
Joined: 08 Aug 2008
Posts: 225

Re: intergers
[#permalink]
Show Tags
11 Nov 2008, 08:28
hit n trial can help here. we can easily guess that either x or y must be 5 here.
if y=5 we cant divide 2000 by 625 ...so x=5...and there u go...
alternatively, we can think of the possible values of (xy)3 ...where (xy)3 =1000 is most plausible option considering y to be an integer....



Intern
Joined: 08 Apr 2014
Posts: 12

Re: If x and y are positive integers and x^3*y^4 = 2000 what is
[#permalink]
Show Tags
08 Apr 2014, 23:52
In such question it is best to see the options available. x^3*y^4 = 2000 is essentially same as (xy)^3*y = 2000 Now, if you look at the available choices, it is 2, 4, 8, 10, 20 You can figure out looking at choices that 2, 4, 8 are too small to satisfy the equation while 20 is too large. Hence, lets check with 10. If xy = 10, xy^3 = 1000, so y = 2000/1000 = 2 and x = 10/2 = 5. 5 & 2 being positive integers, xy=10 is the correct answer.



Manager
Joined: 25 Mar 2013
Posts: 247
Location: United States
Concentration: Entrepreneurship, Marketing
GPA: 3.5

Re: If x and y are positive integers and x^3*y^4 = 2000 what is
[#permalink]
Show Tags
11 Apr 2014, 07:57
My Analysis with Strategy.. 1 Positive Integers ( + ) , 2 Powers , 3 Prime factorization So Prime factorization of 2000 write in Power form = 2^4 5^3 So x = 5 , y = 2 ; 5 * 2 = 10
_________________
I welcome analysis on my posts and kudo +1 if helpful. It helps me to improve my craft.Thank you



eGMAT Representative
Joined: 04 Jan 2015
Posts: 2066

Re: If x and y are positive integers and x^3*y^4 = 2000 what is
[#permalink]
Show Tags
07 May 2015, 04:56



Intern
Joined: 31 May 2015
Posts: 1

Re: If x and y are positive integers and x^3*y^4 = 2000 what is
[#permalink]
Show Tags
31 May 2015, 03:43
X^3Y^4=(XY)^3Y=2000=10^3*2; therefore, Y=2 and XY=10> Answer:D



Intern
Joined: 07 Feb 2015
Posts: 46

Re: If x and y are positive integers and x^3*y^4 = 2000 what is
[#permalink]
Show Tags
01 Jun 2015, 01:07
x^3*y^4=2000 (xy)^3=2000/y=(2/y)*10^3 (xy)=10*(2/y)^(1/3) Since y is a positive integer taking y=2 D
_________________
Kudos if it helped you in any way



EMPOWERgmat Instructor
Status: GMAT Assassin/CoFounder
Affiliations: EMPOWERgmat
Joined: 19 Dec 2014
Posts: 12669
Location: United States (CA)

Re: If x and y are positive integers and x^3*y^4 = 2000 what is
[#permalink]
Show Tags
01 Jun 2015, 21:46
Hi All, This question involves some Number Properties; if you recognize them, think logically and choose the SIMPLEST examples possible, then you'll get to the correct answer relatively quickly. We're told that (X^3)(Y^4) = 2,000 Since we're dealing with a product that ends in 0, at least one of the variables is a multiple of 5 and at least one of the variables is even. So....choose two different numbers....the most obvious multiple of 5 and the most obvious even.... You'll end up with 5 and 2....Plug those in (one for X and one for Y)  it'll take no more than 2 attempts to find the one that 'fits' and you'll have the value of (X)(Y)... Final Answer: GMAT assassins aren't born, they're made, Rich
_________________
760+: Learn What GMAT Assassins Do to Score at the Highest Levels Contact Rich at: Rich.C@empowergmat.com
Rich Cohen
CoFounder & GMAT Assassin
Special Offer: Save $75 + GMAT Club Tests Free
Official GMAT Exam Packs + 70 Pt. Improvement Guarantee www.empowergmat.com/
*****Select EMPOWERgmat Courses now include ALL 6 Official GMAC CATs!*****



Manager
Joined: 21 May 2015
Posts: 240
Concentration: Operations, Strategy

Re: If x and y are positive integers and x^3*y^4 = 2000 what is
[#permalink]
Show Tags
02 Jun 2015, 04:03
D 2 and 5 are in equal numbers in 1000 i.e. 2^3 and 5^3 and thus in 2 x 1000  number of 2 = 1+no. of 5's. Thus there product would be 20.
_________________
Apoorv
I realize that i cannot change the world....But i can play a part



Manager
Joined: 26 Mar 2017
Posts: 134

Re: If x and y are positive integers and x^3*y^4 = 2000 what is
[#permalink]
Show Tags
10 Jun 2017, 07:09
jmyer028 wrote: for this problem, i factored 2000 > 2, 2, 2, 2, 5, 5, 5... or (5*3)(2*4).
based on the factoring, x = 5 and y = 2... so xy = (5)(2) = 10
the correct answer is d. I've done exactly the same Ive got it right in front of me on my test simulation booklet But didn't know what to do with the prime factors (just to nervous) I think if you don't stay calm on test day you'll get nowhere !!
_________________
I hate long and complicated explanations!



EMPOWERgmat Instructor
Status: GMAT Assassin/CoFounder
Affiliations: EMPOWERgmat
Joined: 19 Dec 2014
Posts: 12669
Location: United States (CA)

Re: If x and y are positive integers and x^3*y^4 = 2000 what is
[#permalink]
Show Tags
10 Jun 2017, 11:28
Hi daviddaviddavid, Most of the questions that you'll face on Test Day will become easier to deal with IF you get in the habit of taking notes (including writing down what the question asks you to solve for). After reading through this prompt  and taking all of the necessary notes  the last thing you should have written down is.... "(X)(Y) = ?" In that way, you will know your 'goal' and when you have the necessary information to answer the question that is asked. GMAT assassins aren't born, they're made, Rich
_________________
760+: Learn What GMAT Assassins Do to Score at the Highest Levels Contact Rich at: Rich.C@empowergmat.com
Rich Cohen
CoFounder & GMAT Assassin
Special Offer: Save $75 + GMAT Club Tests Free
Official GMAT Exam Packs + 70 Pt. Improvement Guarantee www.empowergmat.com/
*****Select EMPOWERgmat Courses now include ALL 6 Official GMAC CATs!*****



VP
Status: Learning
Joined: 20 Dec 2015
Posts: 1128
Location: India
Concentration: Operations, Marketing
GPA: 3.4
WE: Engineering (Manufacturing)

Re: If x and y are positive integers and x^3*y^4 = 2000 what is
[#permalink]
Show Tags
10 Jun 2017, 11:49
Imo D 2^4*5^3=2000 hence xy=10 Sent from my ONE E1003 using GMAT Club Forum mobile app
_________________
Please give kudos if you found my answers useful



Manager
Joined: 26 Mar 2017
Posts: 134

If x and y are positive integers and x^3*y^4 = 2000 what is
[#permalink]
Show Tags
Updated on: 10 Jun 2017, 12:11
EMPOWERgmatRichC wrote: Hi daviddaviddavid,
Most of the questions that you'll face on Test Day will become easier to deal with IF you get in the habit of taking notes (including writing down what the question asks you to solve for).
After reading through this prompt  and taking all of the necessary notes  the last thing you should have written down is.... "(X)(Y) = ?"
In that way, you will know your 'goal' and when you have the necessary information to answer the question that is asked.
GMAT assassins aren't born, they're made, Rich thank you =) Ill try my best at the moment I'm just so disappointed. My test is on Tuesday and I just got 570 today When I went through the quant questions again, I could solve at least 10 of them (wrong ones) at ease and within seconds but it appears that I'm just freezing under pressure One questions was x+y = negative ? (1) x negative (2) y positive And I quickly picked C. I guess the algorithm must have thought I'm mentally disabled. I guess selfconfidence and calmness are crucial in order to get a good score. Sorry for offtopic
_________________
I hate long and complicated explanations!




If x and y are positive integers and x^3*y^4 = 2000 what is &nbs
[#permalink]
10 Jun 2017, 11:59



Go to page
1 2
Next
[ 23 posts ]



