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

 It is currently 05 May 2015, 23:41

### 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

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

# Events & Promotions

###### Events & Promotions in June
Open Detailed Calendar

# If z┬▓ - 4z > 5 then which of the following

Author Message
TAGS:
Manager
Joined: 27 Jul 2003
Posts: 124
Location: Singapore
Followers: 1

Kudos [?]: 10 [0], given: 0

If zâ”¬â–“ - 4z > 5 then which of the following [#permalink]  15 Oct 2003, 00:31
00:00

Difficulty:

(N/A)

Question Stats:

0% (00:00) correct 0% (00:00) wrong based on 0 sessions
If z┬▓ - 4z > 5 then which of the following is always true

A) z > -5

B) z < 5

C) z > -1

D) z < 1

E) z < -1
CEO
Joined: 15 Aug 2003
Posts: 3469
Followers: 61

Kudos [?]: 703 [0], given: 781

Re: PS: Which of the following? [#permalink]  15 Oct 2003, 00:46
araspai wrote:
If z┬▓ - 4z > 5 then which of the following is always true

A) z > -5

B) z < 5

C) z > -1

D) z < 1

E) z < -1

(z-5) ( z+1 ) > 0

1.
z-5 >0 AND z +1 >0

z > 5 AND z>-1

2.
z-5 < 0 AND z +1 < 0

Z < 5 AND z<-1

1. either Z > 5 or Z<-1 is always true.

of them, only Z<-1 is there...Answer E
SVP
Joined: 30 Oct 2003
Posts: 1797
Location: NewJersey USA
Followers: 5

Kudos [?]: 41 [0], given: 0

I did not understand you explaination at all.
SVP
Joined: 30 Oct 2003
Posts: 1797
Location: NewJersey USA
Followers: 5

Kudos [?]: 41 [0], given: 0

I did not understand you explaination at all.

if Z > 5 then Z is always > -1

if Z < -1 then Z is always < 5

so you choose the smallest value Z < -1 ?
GMAT Club Legend
Joined: 15 Dec 2003
Posts: 4313
Followers: 27

Kudos [?]: 217 [0], given: 0

z^2 - 4z > 5
z^2 - 4z - 5 > 0
(z+1)(z-5) > 0

Try plugging in values knowing that the treshold values are -1 and 5 and you will see that the condition will hold true whenever you have values for z larger than 5 or less than -1
_________________

Best Regards,

Paul

Intern
Joined: 17 Aug 2003
Posts: 38
Location: USA
Followers: 0

Kudos [?]: 1 [0], given: 0

Re: PS: Which of the following? [#permalink]  30 Dec 2003, 07:20
praetorian123 wrote:
araspai wrote:
If z┬▓ - 4z > 5 then which of the following is always true

A) z > -5

B) z < 5

C) z > -1

D) z < 1

E) z < -1

(z-5) ( z+1 ) > 0

1.
z-5 >0 AND z +1 >0

z > 5 AND z>-1

2.
z-5 < 0 AND z +1 < 0

Z < 5 AND z<-1

1. either Z > 5 or Z<-1 is always true.

of them, only Z<-1 is there...Answer E

praetorian123 can you please explain this. What are the rules for handling quads with inequalities? From your answer it looks like you just factor as normal but apply > and < to the two possible outcomes. Is this correct?

If so how did you get to this part?

1. either Z > 5 or Z<-1 is always true.

how about Z<5 or Z>-1 how did you eliminate these.

It's probably something simple but i can't see it.

Thanks
Re: PS: Which of the following?   [#permalink] 30 Dec 2003, 07:20
Similar topics Replies Last post
Similar
Topics:
If z - 4z > 5 then which of the following is always true 4 15 Aug 2008, 07:40
4 If z^2 - 4z > 5 then which of the following is always 19 21 May 2008, 11:01
If z - 4z > 5 then which of the following is always true 10 04 Nov 2006, 09:57
If z - 4z > 5 then which of the following is always true 2 14 Jul 2006, 14:15
If z - 4z > 5 then which of the following is always true 4 26 May 2005, 02:38
Display posts from previous: Sort by