It is currently 18 Jan 2018, 12:04

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

Events & Promotions

Events & Promotions in June
Open Detailed Calendar

Is st = t ?

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

Hide Tags

1 KUDOS received
Intern
Intern
avatar
Joined: 19 Jul 2013
Posts: 10

Kudos [?]: 8 [1], given: 15

Is st = t ? [#permalink]

Show Tags

New post 07 Jun 2014, 12:04
1
This post received
KUDOS
7
This post was
BOOKMARKED
00:00
A
B
C
D
E

Difficulty:

  15% (low)

Question Stats:

74% (00:34) correct 26% (00:40) wrong based on 253 sessions

HideShow timer Statistics

Is st = t ?

(1) s = st

(2) t = ts
[Reveal] Spoiler: OA

Kudos [?]: 8 [1], given: 15

Expert Post
Math Expert
User avatar
V
Joined: 02 Sep 2009
Posts: 43323

Kudos [?]: 139428 [0], given: 12790

Re: Is st = t ? [#permalink]

Show Tags

New post 07 Jun 2014, 12:13
Expert's post
1
This post was
BOOKMARKED

Kudos [?]: 139428 [0], given: 12790

Manager
Manager
User avatar
Joined: 28 Sep 2013
Posts: 106

Kudos [?]: 36 [0], given: 45

Location: United States (NC)
Concentration: Operations, Technology
WE: Information Technology (Consulting)
Reviews Badge
Re: Is st = t ? [#permalink]

Show Tags

New post 08 Jun 2014, 21:48
Bunuel wrote:
Is st = t ?

Is \(st = t\)? --> is \(s=1\) or \(t=0\) (or both)?

(1) s = st --> \(s=0\) or \(t=1\) (or both). Not sufficient.

(2) t = ts. Directly answers the question. Sufficient.

Answer: B.


Hi Bunuel,

from st (1) : we know that 's' not equals 1 or 't' not equals 0 or both , so is this st not sufficient alone.

Pls clarify
_________________

_________________________________
Consider Kudos if helpful

Kudos [?]: 36 [0], given: 45

Expert Post
Math Expert
User avatar
V
Joined: 02 Sep 2009
Posts: 43323

Kudos [?]: 139428 [0], given: 12790

Re: Is st = t ? [#permalink]

Show Tags

New post 09 Jun 2014, 01:02
Expert's post
1
This post was
BOOKMARKED
thoufique wrote:
Bunuel wrote:
Is st = t ?

Is \(st = t\)? --> is \(s=1\) or \(t=0\) (or both)?

(1) s = st --> \(s=0\) or \(t=1\) (or both). Not sufficient.

(2) t = ts. Directly answers the question. Sufficient.

Answer: B.


Hi Bunuel,

from st (1) : we know that 's' not equals 1 or 't' not equals 0 or both , so is this st not sufficient alone.

Pls clarify


Consider this:
If \(s=0\) and \(t\neq{0}\) (\(s = st\)), then \(st\neq{t}\). Or if \(t=1\) and \(s\neq{1}\) (\(s = st\)), then \(st\neq{t}\). So, for these cases the answer to the question is NO.

If \(s=t=0\) (\(s = st\)), then \(st={t}\). Or if \(s=t=1\) (\(s = st\)), then \(st={t}\). So, for these cases the answer to the question is YES.

Does this make sense?
_________________

New to the Math Forum?
Please read this: Ultimate GMAT Quantitative Megathread | All You Need for Quant | PLEASE READ AND FOLLOW: 12 Rules for Posting!!!

Resources:
GMAT Math Book | Triangles | Polygons | Coordinate Geometry | Factorials | Circles | Number Theory | Remainders; 8. Overlapping Sets | PDF of Math Book; 10. Remainders | GMAT Prep Software Analysis | SEVEN SAMURAI OF 2012 (BEST DISCUSSIONS) | Tricky questions from previous years.

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?
Extra-hard Quant Tests with Brilliant Analytics

Kudos [?]: 139428 [0], given: 12790

Manager
Manager
User avatar
Joined: 28 Sep 2013
Posts: 106

Kudos [?]: 36 [0], given: 45

Location: United States (NC)
Concentration: Operations, Technology
WE: Information Technology (Consulting)
Reviews Badge
Re: Is st = t ? [#permalink]

Show Tags

New post 09 Jun 2014, 09:12
Quote:
Consider this:
If \(s=0\) and \(t\neq{0}\) (\(s = st\)), then \(st\neq{t}\). Or if \(t=1\) and \(s\neq{1}\) (\(s = st\)), then \(st\neq{t}\). So, for these cases the answer to the question is NO.

If \(s=t=0\) (\(s = st\)), then \(st={t}\). Or if \(s=t=1\) (\(s = st\)), then \(st={t}\). So, for these cases the answer to the question is YES.

Does this make sense?



Yes Bunuel, when we consider values it makes sense.
But I am unable to get to this directly with out plugging values.
_________________

_________________________________
Consider Kudos if helpful

Kudos [?]: 36 [0], given: 45

1 KUDOS received
Manager
Manager
avatar
B
Joined: 26 Mar 2017
Posts: 160

Kudos [?]: 14 [1], given: 1

Re: Is st = t ? [#permalink]

Show Tags

New post 10 Jun 2017, 07:13
1
This post received
KUDOS
Bunuel wrote:
Is st = t ?

Is \(st = t\)? --> is \(s=1\) or \(t=0\) (or both)?

(1) s = st --> \(s=0\) or \(t=1\) (or both). Not sufficient.

(2) t = ts. Directly answers the question. Sufficient.

Answer: B.



For (1)

could be also assume following cases ?

case 1: s=t=0 then s=st

case 2: s=5,t=1 then s≠st

thanks =)
_________________

I hate long and complicated explanations!

Kudos [?]: 14 [1], given: 1

Intern
Intern
avatar
B
Joined: 20 Feb 2017
Posts: 44

Kudos [?]: 6 [0], given: 437

Re: Is st = t ? [#permalink]

Show Tags

New post 08 Dec 2017, 10:02
Bunuel wrote:
Is st = t ?

Is \(st = t\)? --> is \(s=1\) or \(t=0\) (or both)?

(1) s = st --> \(s=0\) or \(t=1\) (or both). Not sufficient.

(2) t = ts. Directly answers the question. Sufficient.

Answer: B.

@bunnel If we have a statement that restates the question , then it becomes insufficient as we don't have any additional information to answer the question. But here the equality nullifies it and directly answers the question. Hence it is sufficient. IS this reasoning correct ?
i

Kudos [?]: 6 [0], given: 437

Expert Post
Math Expert
User avatar
V
Joined: 02 Sep 2009
Posts: 43323

Kudos [?]: 139428 [0], given: 12790

Re: Is st = t ? [#permalink]

Show Tags

New post 08 Dec 2017, 10:09
Raksat wrote:
Bunuel wrote:
Is st = t ?

Is \(st = t\)? --> is \(s=1\) or \(t=0\) (or both)?

(1) s = st --> \(s=0\) or \(t=1\) (or both). Not sufficient.

(2) t = ts. Directly answers the question. Sufficient.

Answer: B.

@bunnel If we have a statement that restates the question , then it becomes insufficient as we don't have any additional information to answer the question. But here the equality nullifies it and directly answers the question. Hence it is sufficient. IS this reasoning correct ?
i


Not sure I can follow you.

Say the question asks: is x = 1? And (1) says that x = 1. In this case (1) is sufficient as it directly answers the question: YES x does equal to 1. This is EXACTLY the case we have with the above question.
_________________

New to the Math Forum?
Please read this: Ultimate GMAT Quantitative Megathread | All You Need for Quant | PLEASE READ AND FOLLOW: 12 Rules for Posting!!!

Resources:
GMAT Math Book | Triangles | Polygons | Coordinate Geometry | Factorials | Circles | Number Theory | Remainders; 8. Overlapping Sets | PDF of Math Book; 10. Remainders | GMAT Prep Software Analysis | SEVEN SAMURAI OF 2012 (BEST DISCUSSIONS) | Tricky questions from previous years.

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?
Extra-hard Quant Tests with Brilliant Analytics

Kudos [?]: 139428 [0], given: 12790

Intern
Intern
avatar
B
Joined: 20 Feb 2017
Posts: 44

Kudos [?]: 6 [0], given: 437

Re: Is st = t ? [#permalink]

Show Tags

New post 08 Dec 2017, 10:54
Bunuel wrote:
Raksat wrote:
Bunuel wrote:
Is st = t ?

Is \(st = t\)? --> is \(s=1\) or \(t=0\) (or both)?

(1) s = st --> \(s=0\) or \(t=1\) (or both). Not sufficient.

(2) t = ts. Directly answers the question. Sufficient.

Answer: B.

@bunnel If we have a statement that restates the question , then it becomes insufficient as we don't have any additional information to answer the question. But here the equality nullifies it and directly answers the question. Hence it is sufficient. IS this reasoning correct ?
i


Not sure I can follow you.


Say the question asks: is x = 1? And (1) says that x = 1. In this case (1) is sufficient as it directly answers the question: YES x does equal to 1. This is EXACTLY the case we have with the above question.




Its about the difference between a tautological statement and this question. Reference question : https://gmatclub.com/forum/in-the-diagr ... 94414.html
In the explanation you explained " This statement repeats information in the prompt, and contains no new information, so it doesn’t help us at all to figure out anything else. This statement, alone and by itself, is not sufficient."
Here B is also reintroducing the information in question.
what's the difference ?

Kudos [?]: 6 [0], given: 437

Expert Post
1 KUDOS received
Math Expert
User avatar
V
Joined: 02 Sep 2009
Posts: 43323

Kudos [?]: 139428 [1], given: 12790

Re: Is st = t ? [#permalink]

Show Tags

New post 08 Dec 2017, 11:00
1
This post received
KUDOS
Expert's post
Raksat wrote:
Bunuel wrote:
Raksat wrote:
@bunnel If we have a statement that restates the question , then it becomes insufficient as we don't have any additional information to answer the question. But here the equality nullifies it and directly answers the question. Hence it is sufficient. IS this reasoning correct ?
i


Not sure I can follow you.


Say the question asks: is x = 1? And (1) says that x = 1. In this case (1) is sufficient as it directly answers the question: YES x does equal to 1. This is EXACTLY the case we have with the above question.




Its about the difference between a tautological statement and this question. Reference question : https://gmatclub.com/forum/in-the-diagr ... 94414.html
In the explanation you explained " This statement repeats information in the prompt, and contains no new information, so it doesn’t help us at all to figure out anything else. This statement, alone and by itself, is not sufficient."
Here B is also reintroducing the information in question.
what's the difference ?


In the question you quote one of the statements says something that is generally true, so it adds not new info. It says something like x = x, that is generally true.

Here the question asks is \(st = t\)? (2) says t = ts. So, it gives an YES answer to the question.
_________________

New to the Math Forum?
Please read this: Ultimate GMAT Quantitative Megathread | All You Need for Quant | PLEASE READ AND FOLLOW: 12 Rules for Posting!!!

Resources:
GMAT Math Book | Triangles | Polygons | Coordinate Geometry | Factorials | Circles | Number Theory | Remainders; 8. Overlapping Sets | PDF of Math Book; 10. Remainders | GMAT Prep Software Analysis | SEVEN SAMURAI OF 2012 (BEST DISCUSSIONS) | Tricky questions from previous years.

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?
Extra-hard Quant Tests with Brilliant Analytics

Kudos [?]: 139428 [1], given: 12790

Re: Is st = t ?   [#permalink] 08 Dec 2017, 11:00
Display posts from previous: Sort by

Is st = t ?

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


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