Find all School-related info fast with the new School-Specific MBA Forum

It is currently 20 Aug 2014, 10:43

Flash Sale:

The Economist GMAT Tutor - 15% Off All Courses


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.

Events & Promotions

Events & Promotions in June
Open Detailed Calendar

If 0 < r < 1 < s < 2, which of the following must be less

  Question banks Downloads My Bookmarks Reviews Important topics  
Author Message
TAGS:
Senior Manager
Senior Manager
avatar
Joined: 11 May 2010
Posts: 289
Location: United Kingdom
Concentration: Entrepreneurship, Technology
GMAT Date: 10-22-2011
GPA: 3
WE: Information Technology (Internet and New Media)
Followers: 4

Kudos [?]: 29 [0], given: 12

If 0 < r < 1 < s < 2, which of the following must be less [#permalink] New post 25 Oct 2010, 10:56
3
This post was
BOOKMARKED
00:00
A
B
C
D
E

Difficulty:

  25% (medium)

Question Stats:

65% (01:23) correct 35% (00:21) wrong based on 132 sessions
If 0 < r < 1 < s < 2, which of the following must be less than 1?

I. r/s
II. rs
III. s - r

A. I only
B. II only
C. III only
D. I and II
E. I and III

OPEN DISCUSSION OF THIS QUESTION IS HERE: if-0-r-1-s-2-which-of-the-following-must-be-less-than-128112.html
[Reveal] Spoiler: OA
Kaplan Promo CodeKnewton GMAT Discount CodesVeritas Prep GMAT Discount Codes
4 KUDOS received
Retired Moderator
User avatar
Joined: 02 Sep 2010
Posts: 807
Location: London
Followers: 77

Kudos [?]: 465 [4] , given: 25

GMAT ToolKit User GMAT Tests User Reviews Badge
Re: GMAT Prep - If 0 < r < 1 < s < 2, which of the following..?? [#permalink] New post 25 Oct 2010, 11:07
4
This post received
KUDOS
n2739178 wrote:
GMAT Prep question... What's the easiest way to solve this using MGMAT style case-charts?

Attachment:
q2.jpg


Not sure what you mean by MGMAT style case charts. But this question is quite straight forward

For r,s positive : r/s is less than 1, when r<s. which we know

rs : No need for this to be less than 1 (r could be almost 1 and s could be 1.5 or 1.7)

s-r : No need for this to be less than 1 (r could be almost 0 and s could be 1.5 or 1.7)

Think of extreme cases in such questions, you should always be able to find the exception like that
_________________

Math write-ups
1) Algebra-101 2) Sequences 3) Set combinatorics 4) 3-D geometry

My GMAT story

Get the best GMAT Prep Resources with GMAT Club Premium Membership

Senior Manager
Senior Manager
avatar
Joined: 11 May 2010
Posts: 289
Location: United Kingdom
Concentration: Entrepreneurship, Technology
GMAT Date: 10-22-2011
GPA: 3
WE: Information Technology (Internet and New Media)
Followers: 4

Kudos [?]: 29 [0], given: 12

Re: GMAT Prep - If 0 < r < 1 < s < 2, which of the following..?? [#permalink] New post 25 Oct 2010, 13:28
aaa yes of course - extreme cases - that's what I remember MGMAT going on about for these sorts of questions - awesome, thanks!
Intern
Intern
avatar
Joined: 28 Apr 2012
Posts: 22
Followers: 0

Kudos [?]: 6 [0], given: 19

Re: GMAT Prep - If 0 < r < 1 < s < 2, which of the following..?? [#permalink] New post 10 May 2012, 05:03
Is the following true:

If r and s are positive numbers and s > r, then r/s will always be < 1.
Expert Post
2 KUDOS received
Math Expert
User avatar
Joined: 02 Sep 2009
Posts: 19030
Followers: 3361

Kudos [?]: 24381 [2] , given: 2677

Re: GMAT Prep - If 0 < r < 1 < s < 2, which of the following..?? [#permalink] New post 10 May 2012, 05:14
2
This post received
KUDOS
Expert's post
honsmos wrote:
Is the following true:

If r and s are positive numbers and s > r, then r/s will always be < 1.


If given that r>0, s>0 and s>r then divide s>r by s (we can safely do that since s>0): 1>r/s.

Complete solution:

If 0 < r < 1 < s < 2, which of the following must be less than 1?
I. r/s
II. rs
III. s - r

A. I only
B. II only
C. III only
D. I and II
E. I and III

Notice that we are asked "which of the following MUST be lees than 1, not COULD be less than 1. For such kind of questions if you can prove that a statement is NOT true for one particular set of numbers, it will mean that this statement is not always true and hence not a correct answer.

Given: 0 < r < s --> divide by s (we can safely do this since we know that s>0) --> \frac{r}{s}<1, so I must be true;

II. rs: if r=\frac{9}{10}<1 and 1<(s=\frac{10}{9})<2 then rs=1, so this statement is not alway true;

III. s-r: if r=0.5<1 and 1<(s=1.5)<2 then s-r=1, so this statement is not alway true.

Answer: A (I only).

Check our new Must or Could be True Questions to practice more: search.php?search_id=tag&tag_id=193

Hope it helps.

OPEN DISCUSSION OF THIS QUESTION IS HERE: if-0-r-1-s-2-which-of-the-following-must-be-less-than-128112.html
_________________

NEW TO MATH FORUM? PLEASE READ THIS: ALL YOU NEED FOR QUANT!!!

PLEASE READ AND FOLLOW: 11 Rules for Posting!!!

RESOURCES: [GMAT MATH BOOK]; 1. Triangles; 2. Polygons; 3. Coordinate Geometry; 4. Factorials; 5. Circles; 6. Number Theory; 7. Remainders; 8. Overlapping Sets; 9. PDF of Math Book; 10. Remainders; 11. GMAT Prep Software Analysis NEW!!!; 12. SEVEN SAMURAI OF 2012 (BEST DISCUSSIONS) NEW!!!; 12. Tricky questions from previous years. NEW!!!;

COLLECTION OF QUESTIONS:
PS: 1. Tough and Tricky questions; 2. Hard questions; 3. Hard questions part 2; 4. Standard deviation; 5. Tough Problem Solving Questions With Solutions; 6. Probability and Combinations Questions With Solutions; 7 Tough and tricky exponents and roots questions; 8 12 Easy Pieces (or not?); 9 Bakers' Dozen; 10 Algebra set. ,11 Mixed Questions, 12 Fresh Meat

DS: 1. DS tough questions; 2. DS tough questions part 2; 3. DS tough questions part 3; 4. DS Standard deviation; 5. Inequalities; 6. 700+ GMAT Data Sufficiency Questions With Explanations; 7 Tough and tricky exponents and roots questions; 8 The Discreet Charm of the DS ; 9 Devil's Dozen!!!; 10 Number Properties set., 11 New DS set.


What are GMAT Club Tests?
25 extra-hard Quant Tests

Get the best GMAT Prep Resources with GMAT Club Premium Membership

Re: GMAT Prep - If 0 < r < 1 < s < 2, which of the following..??   [#permalink] 10 May 2012, 05:14
    Similar topics Author Replies Last post
Similar
Topics:
1 Experts publish their posts in the topic If 0<r<1<s<2. Which of the following must be less than 1. devinawilliam83 5 25 Feb 2012, 01:06
4 Experts publish their posts in the topic If 0 < r < 1 < s < 2, which of the following must be less azule45 6 21 Jan 2011, 10:24
1 If 0 < r < 1 < s < 2, which of the following chenhong1224 2 10 Oct 2008, 10:29
If 0 < r < 1 < s < 2, which of the following nfa1rhp 1 09 Aug 2007, 11:01
If 0<r<1<s<2, which of the following must be uphillclimb 3 21 Oct 2006, 09:55
Display posts from previous: Sort by

If 0 < r < 1 < s < 2, which of the following must be less

  Question banks Downloads My Bookmarks Reviews Important topics  


GMAT Club MBA Forum Home| About| Privacy Policy| Terms and Conditions| GMAT Club Rules| Contact| Sitemap

Powered by phpBB © phpBB Group and phpBB SEO

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®.