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

It is currently 14 Aug 2018, 22:03

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

If r, s are positive integers, is r/s a terminating decimal?

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

Hide Tags

Math Revolution GMAT Instructor
User avatar
V
Joined: 16 Aug 2015
Posts: 6006
GMAT 1: 760 Q51 V42
GPA: 3.82
Premium Member
If r, s are positive integers, is r/s a terminating decimal?  [#permalink]

Show Tags

New post 16 Mar 2018, 00:52
00:00
A
B
C
D
E

Difficulty:

  25% (medium)

Question Stats:

77% (00:34) correct 23% (00:42) wrong based on 39 sessions

HideShow timer Statistics

[GMAT math practice question]

If \(r, s\) are positive integers, is \(\frac{r}{s}\) a terminating decimal?

1) \(\frac{1}{r^2}\) is a terminating decimal
2) \(\frac{1}{s^2}\) is a terminating decimal

_________________

MathRevolution: Finish GMAT Quant Section with 10 minutes to spare
The one-and-only World’s First Variable Approach for DS and IVY Approach for PS with ease, speed and accuracy.
"Only $99 for 3 month Online Course"
"Free Resources-30 day online access & Diagnostic Test"
"Unlimited Access to over 120 free video lessons - try it yourself"

Intern
Intern
avatar
Joined: 04 Jan 2018
Posts: 1
GMAT 1: 670 Q50 V30
CAT Tests
Re: If r, s are positive integers, is r/s a terminating decimal?  [#permalink]

Show Tags

New post 16 Mar 2018, 01:49
Is it B?

Working:

For 1/(x^2) to be a terminating decimal, x has to be either power or a multiple of (1,2,5).

Stmt 1. Insufficient as terminating decimal depends on denominator.

Stmt 2. Sufficient, as s is a multiple or power of (1,2,5) and whatever is value of r, r/s will be terminating decimal.

Sent from my Lenovo P1a42 using GMAT Club Forum mobile app
Math Revolution GMAT Instructor
User avatar
V
Joined: 16 Aug 2015
Posts: 6006
GMAT 1: 760 Q51 V42
GPA: 3.82
Premium Member
Re: If r, s are positive integers, is r/s a terminating decimal?  [#permalink]

Show Tags

New post 18 Mar 2018, 23:17
=>

Forget conventional ways of solving math questions. For DS problems, the VA (Variable Approach) method is the quickest and easiest way to find the answer without actually solving the problem. Remember that equal numbers of variables and independent equations ensure a solution.

The first step of the VA (Variable Approach) method is to modify the original condition and the question. We then recheck the question.

We can modify the question as follows:
\(\frac{r}{s}\) is a terminating decimal if and only if s has no other prime factors than \(2\) and \(5\).
This is the same as condition 2). Condition 1) tells us nothing about the prime factors of s.

Therefore, B is the answer.


Answer: B
_________________

MathRevolution: Finish GMAT Quant Section with 10 minutes to spare
The one-and-only World’s First Variable Approach for DS and IVY Approach for PS with ease, speed and accuracy.
"Only $99 for 3 month Online Course"
"Free Resources-30 day online access & Diagnostic Test"
"Unlimited Access to over 120 free video lessons - try it yourself"

Re: If r, s are positive integers, is r/s a terminating decimal? &nbs [#permalink] 18 Mar 2018, 23:17
Display posts from previous: Sort by

If r, s are positive integers, is r/s a terminating decimal?

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

Events & Promotions

PREV
NEXT


GMAT Club MBA Forum Home| About| Terms and Conditions and Privacy Policy| 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®.