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.

It appears that you are browsing the GMAT Club forum unregistered!

Signing up is free, quick, and confidential.
Join other 500,000 members and get the full benefits of GMAT Club

Registration gives you:

Tests

Take 11 tests and quizzes from GMAT Club and leading GMAT prep companies such as Manhattan GMAT,
Knewton, and others. All are free for GMAT Club members.

Applicant Stats

View detailed applicant stats such as GPA, GMAT score, work experience, location, application
status, and more

Books/Downloads

Download thousands of study notes,
question collections, GMAT Club’s
Grammar and Math books.
All are free!

Thank you for using the timer!
We noticed you are actually not timing your practice. Click the START button first next time you use the timer.
There are many benefits to timing your practice, including:

(1) s^2 – s < 0 --> \(s(s-1)<0\) --> \(0<s<1\) --> s is positive. We know nothing about t. Not sufficient.

(2) \(\frac{s-4}{t-3}=1\) --> \(s=t+1\). If \(s=11\) and \(t=10\), then \(st>0\) but if \(s=0.5\) ans \(t=-0.5\), then \(st<0\). Not sufficient.

(1)+(2) Since from (2) \(s=t+1\), then from (1) we have that \(0<t+1<1\) --> \(-1<t<0\), so we have that t is negative. Therefore st = positive*negative = negative. Sufficient.

(1) s^2 – s < 0 --> \(s(s-1)<0\) --> \(0<s<1\) --> s is positive. We know nothing about t. Not sufficient.

(2) \(\frac{s-4}{t-3}=1\) --> \(s=t+1\). If \(s=11\) and \(t=10\), then \(st>0\) but if \(s=0.5\) ans \(t=-0.5\), then \(st<0\). Not sufficient.

(1)+(2) Since from (2) \(s=t+1\), then from (1) we have that \(0<t+1<1\) --> \(-1<t<0\), so we have that t is negative. Therefore st = positive*negative = negative. Sufficient.

Answer: C.

Hope it's clear.

Well I did this other way around.

St 1 - s^2 -s <0 ( we need both s and t ) not sufficient

St 2- s-4/t-3 =1, from this we get => s-4=t-3 => s-1=t, not sufficient

From both we get, from St 1 s(s-1)<0 and St 2 says s-1=t, if we replace s-1 with t, we get

(1) s^2 – s < 0 --> \(s(s-1)<0\) --> \(0<s<1\) --> s is positive. We know nothing about t. Not sufficient.

(2) \(\frac{s-4}{t-3}=1\) --> \(s=t+1\). If s=10 and t=11, then st>0 but if s=-0.5 ans t=0.5, then st<0. Not sufficient.

(1)+(2) Since from (2) \(s=t+1\), then from (1) we have that \(0<t+1<1\) --> \(-1<t<0\), so we have that t is negative. Therefore st = positive*negative = negative. Sufficient.

Answer: C.

Hope it's clear.

Bunuel,

I am confused with the one...

In Stm2

S-t = 1

I thought both S and T will have same sign to get 1

E.g- S= 5, t= 4

S-T = 4

S= -4, T= -5

-4-(-5) = 1

In both the case S and T are having same sign and definitely ST is not negative....

Pls explain what am I missing??

Thanks
_________________

"Where are my Kudos" ............ Good Question = kudos

(1) s^2 – s < 0 --> \(s(s-1)<0\) --> \(0<s<1\) --> s is positive. We know nothing about t. Not sufficient.

(2) \(\frac{s-4}{t-3}=1\) --> \(s=t+1\). If s=10 and t=11, then st>0 but if s=0.5 ans t=-0.5, then st<0. Not sufficient.

(1)+(2) Since from (2) \(s=t+1\), then from (1) we have that \(0<t+1<1\) --> \(-1<t<0\), so we have that t is negative. Therefore st = positive*negative = negative. Sufficient.

Answer: C.

Hope it's clear.

Bunuel,

I am confused with the one...

In Stm2

S-t = 1

I thought both S and T will have same sign to get 1

E.g- S= 5, t= 4

S-T = 4

S= -4, T= -5

-4-(-5) = 1

In both the case S and T are having same sign and definitely ST is not negative....

Pls explain what am I missing??

Thanks

In post you are quoting there is an example giving negative product: \(s=0.5\) ans \(t=-0.5\), then \(st<0\).
_________________

A)Statement (1) ALONE is sufficient, but statement (2) alone is not sufficient. B)Statement (2) ALONE is sufficient, but statement (1) alone is not sufficient. C)Both statements TOGETHER are sufficient, but NEITHER one ALONE is sufficient. D)EACH statement ALONE is sufficient. E)Statements (1) and (2) TOGETHER are NOT sufficient.

A)Statement (1) ALONE is sufficient, but statement (2) alone is not sufficient. B)Statement (2) ALONE is sufficient, but statement (1) alone is not sufficient. C)Both statements TOGETHER are sufficient, but NEITHER one ALONE is sufficient. D)EACH statement ALONE is sufficient. E)Statements (1) and (2) TOGETHER are NOT sufficient.

Merging similar topics. Please refer to the discussion above.
_________________

(1) s^2 – s < 0 --> \(s(s-1)<0\) --> \(0<s<1\) --> s is positive. We know nothing about t. Not sufficient.

(2) \(\frac{s-4}{t-3}=1\) --> \(s=t+1\). If \(s=11\) and \(t=10\), then \(st>0\) but if \(s=0.5\) ans \(t=-0.5\), then \(st<0\). Not sufficient.

(1)+(2) Since from (2) \(s=t+1\), then from (1) we have that \(0<t+1<1\) --> \(-1<t<0\), so we have that t is negative. Therefore st = positive*negative = negative. Sufficient.

Answer: C.

Hope it's clear.

For last 30 mins i am pondering on this B statement ...superb , & when i searched it over here, i was sure you must have already address it...& now i understand what i am missing !!!

I want to Kill DS....10 days to Exam only !!!
_________________

(1) s^2 – s < 0 --> \(s(s-1)<0\) --> \(0<s<1\) --> s is positive. We know nothing about t. Not sufficient.

(2) \(\frac{s-4}{t-3}=1\) --> \(s=t+1\). If \(s=11\) and \(t=10\), then \(st>0\) but if \(s=0.5\) ans \(t=-0.5\), then \(st<0\). Not sufficient.

(1)+(2) Since from (2) \(s=t+1\), then from (1) we have that \(0<t+1<1\) --> \(-1<t<0\), so we have that t is negative. Therefore st = positive*negative = negative. Sufficient.

Answer: C.

Hope it's clear.

Bunuel,

This might be a stupid question but for some reason I struggle with this.

in the following step: (s−4)/(t−3)=1 so s-4=t-3 so s=t+1

How can you multiply by an unknown variable if you don't know if the variable is zero? Does this rule only apply if the variable is the only figure in the denominator? or does it only apply when dividing by an unknown variable?

(1) s^2 – s < 0 --> \(s(s-1)<0\) --> \(0<s<1\) --> s is positive. We know nothing about t. Not sufficient.

(2) \(\frac{s-4}{t-3}=1\) --> \(s=t+1\). If \(s=11\) and \(t=10\), then \(st>0\) but if \(s=0.5\) ans \(t=-0.5\), then \(st<0\). Not sufficient.

(1)+(2) Since from (2) \(s=t+1\), then from (1) we have that \(0<t+1<1\) --> \(-1<t<0\), so we have that t is negative. Therefore st = positive*negative = negative. Sufficient.

Answer: C.

Hope it's clear.

Bunuel,

This might be a stupid question but for some reason I struggle with this.

in the following step: (s−4)/(t−3)=1 so s-4=t-3 so s=t+1

How can you multiply by an unknown variable if you don't know if the variable is zero? Does this rule only apply if the variable is the only figure in the denominator? or does it only apply when dividing by an unknown variable?

Thanks in advance!

We know that t-3 is not 0, because if it were, then (s−4)/(t−3) would be undefined and not equal to 1.
_________________

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.
_________________

Version 8.1 of the WordPress for Android app is now available, with some great enhancements to publishing: background media uploading. Adding images to a post or page? Now...

“Keep your head down, and work hard. Don’t attract any attention. You should be grateful to be here.” Why do we keep quiet? Being an immigrant is a constant...

“Keep your head down, and work hard. Don’t attract any attention. You should be grateful to be here.” Why do we keep quiet? Being an immigrant is a constant...