Last visit was: 26 Apr 2024, 11:11 It is currently 26 Apr 2024, 11:11

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
User avatar
Manager
Manager
Joined: 17 Nov 2009
Posts: 204
Own Kudos [?]: 262 [56]
Given Kudos: 17
Send PM
Most Helpful Reply
Math Expert
Joined: 02 Sep 2009
Posts: 92948
Own Kudos [?]: 619215 [7]
Given Kudos: 81609
Send PM
General Discussion
User avatar
Manager
Manager
Joined: 14 Jun 2010
Posts: 130
Own Kudos [?]: 68 [1]
Given Kudos: 7
Send PM
User avatar
Retired Moderator
Joined: 02 Sep 2010
Posts: 615
Own Kudos [?]: 2931 [0]
Given Kudos: 25
Location: London
 Q51  V41
Send PM
Re: If x, y, and n are positive integers, is (x/y)^n greater than 1,000 ? [#permalink]
psychomath wrote:
HI Bunuel,

I have a small doubt here....Do positive integers include zero too? If so, we have an undefined value as the answer right? Kinly clarify


Nope .. 0 is neither positive nor negative
User avatar
Manager
Manager
Joined: 14 Jun 2010
Posts: 130
Own Kudos [?]: 68 [0]
Given Kudos: 7
Send PM
Re: If x, y, and n are positive integers, is (x/y)^n greater than 1,000 ? [#permalink]
OK so what i remember about zero being a positive integer is wrong...Thanks a ton!
User avatar
Manager
Manager
Joined: 25 Feb 2010
Posts: 208
Own Kudos [?]: 320 [0]
Given Kudos: 10
Send PM
Re: If x, y, and n are positive integers, is (x/y)^n greater than 1,000 ? [#permalink]
Bunuel wrote:

(2) x>5y and n>x --> \(\frac{x}{y}>5\) also as \(x\), \(y\), and \(n\) are positive integers then the least value of \(x\) is 6 (for \(y=1\)) and the least value of \(n\) is 7 --> so we would have \((# \ more \ than \ 5)^{(at \ least \ 7)}\) which is more than 1,000 (5^7>1,000). Sufficient.

Answer: B.


Can you please explain the 2nd equation again.
I didn;t get this one.
Math Expert
Joined: 02 Sep 2009
Posts: 92948
Own Kudos [?]: 619215 [1]
Given Kudos: 81609
Send PM
Re: If x, y, and n are positive integers, is (x/y)^n greater than 1,000 ? [#permalink]
1
Kudos
Expert Reply
onedayill wrote:
Bunuel wrote:

(2) x>5y and n>x --> \(\frac{x}{y}>5\) also as \(x\), \(y\), and \(n\) are positive integers then the least value of \(x\) is 6 (for \(y=1\)) and the least value of \(n\) is 7 --> so we would have \((# \ more \ than \ 5)^{(at \ least \ 7)}\) which is more than 1,000 (5^7>1,000). Sufficient.

Answer: B.


Can you please explain the 2nd equation again.
I didn;t get this one.


Question: is \((\frac{x}{y})^n>1,00\)?

From (2):

\(x>5y\) --> \(\frac{x}{y}>5\), so \(base=\frac{x}{y}=(# \ more \ than \ 5)\);

\(x>5y\) and \(n>x\) --> as \(x\), \(y\), and \(n\) are positive integers then: the least value \(y\) is 1 --> the least value of \(x\) is 6 (\(x>5=5y_{min}\)) --> the least value of \(n\) is 7 (as \(n>x\));

Is \((\frac{x}{y})^n>1,00\) --> is \((# \ more \ than \ 5)^{(at \ least \ 7)}\)? Answer is YES, as even \(5^7>1,000\).

Hope it's clear.
Retired Moderator
Joined: 16 Nov 2010
Posts: 909
Own Kudos [?]: 1173 [0]
Given Kudos: 43
Location: United States (IN)
Concentration: Strategy, Technology
Send PM
Re: If x, y, and n are positive integers, is (x/y)^n greater than 1,000 ? [#permalink]
Let us substitute numbers to disprove/prove the choices :

We need to predict whether (x/y)^n > 1000

(1) x = y^3 and n > y.

if y = 1 and x = 1 , and n = 2, then it's false.

if y = 10, x = 1000 and n = 1001, it's true

Insufficient

(2) x > 5y and n > x.

Let us take lowest value of y = 1
Then x = 6 at least , and n = 7 at least

So 6^7 > 1000

Another way to look at this is :

x > 5y
=> x/y > 5 and n > 5x => n >= 5 (because these are all positive numbers)

So 5^5 > 1000

Sufficient.

Answer - B
Math Expert
Joined: 02 Sep 2009
Posts: 92948
Own Kudos [?]: 619215 [1]
Given Kudos: 81609
Send PM
Re: If x, y, and n are positive integers, is (x/y)^n greater than 1,000 ? [#permalink]
1
Bookmarks
Expert Reply
Bumping for review and further discussion*. Get a kudos point for an alternative solution!

*New project from GMAT Club!!! Check HERE

Theory on Exponents: math-number-theory-88376.html

All DS Exponents questions to practice: search.php?search_id=tag&tag_id=39
All PS Exponents questions to practice: search.php?search_id=tag&tag_id=60

Tough and tricky DS exponents and roots questions with detailed solutions: tough-and-tricky-exponents-and-roots-questions-125967.html
Tough and tricky PS exponents and roots questions with detailed solutions: tough-and-tricky-exponents-and-roots-questions-125956.html
User avatar
Director
Director
Joined: 25 Apr 2012
Posts: 531
Own Kudos [?]: 2284 [1]
Given Kudos: 740
Location: India
GPA: 3.21
WE:Business Development (Other)
Send PM
Re: If x, y, and n are positive integers, is (x/y)^n greater than 1,000 ? [#permalink]
1
Kudos
agnok wrote:
If x, y, and n are positive integers, is (x/y)^n greater than 1,000 ?

(1) x=y^3 and n>y
(2) x>5y and n>x


Given x,y and n are positive integers

From st 1 we have x= y^3 and n>y so the given expression becomes

(y^2)^n > 1000

now if y = 2 and n = 5 we have 4^5>1000----> yes
but if y=1 and n=5 then we have 1^5>1000-----> no

Not sufficient

St 2 says x>5y and n>x

Let us assume x= 5y so we have 5^n > 1000

now also n> x so if x= 5 then n can be any value integer greater than 5 ----> 5^n>1000 is definitely true
now since x>5y then ----> value of x is more than 5 and since n>x it will always be greater than 1000

Hence ans B
Alum
Joined: 12 Aug 2015
Posts: 2282
Own Kudos [?]: 3132 [0]
Given Kudos: 893
GRE 1: Q169 V154
Send PM
Re: If x, y, and n are positive integers, is (x/y)^n greater than 1,000 ? [#permalink]
agnok wrote:
If x, y, and n are positive integers, is (x/y)^n greater than 1,000 ?

(1) x=y^3 and n>y
(2) x>5y and n>x



Excellent Question,,
Here i just plugged in y=1 to calculate the least value of LHS as y increases x increases and so does n hence B is correct
User avatar
Non-Human User
Joined: 09 Sep 2013
Posts: 32688
Own Kudos [?]: 822 [0]
Given Kudos: 0
Send PM
Re: If x, y, and n are positive integers, is (x/y)^n greater than 1,000 ? [#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, y, and n are positive integers, is (x/y)^n greater than 1,000 ? [#permalink]
Moderator:
Math Expert
92947 posts

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