BREAKING: Target Test Prep releases Brand New 2026 On Demand GMAT prep course

Redeem

Is |p| =

This topic has expert replies
Post new topic Post Reply
Previous Topic Next Topic
User avatar
GMAT Instructor
Posts: 3650
Joined: Wed Jan 21, 2009 4:27 am
Location: India
Thanked: 267 times
Followed by:80 members
GMAT Score:760

Is |p| =

by sanju09 » Tue May 18, 2010 5:12 am
Is |p| = q - r?
(1) p + q = r.
(2) p < 0.
The mind is everything. What you think you become. -Lord Buddha



Sanjeev K Saxena
Quantitative Instructor
The Princeton Review - Manya Abroad
Lucknow-226001

www.manyagroup.com
Top
Source: — Data Sufficiency |
Newbie | Next Rank: 10 Posts
Posts: 9
Joined: Mon May 10, 2010 1:23 am

by raviki8208 » Tue May 18, 2010 8:37 am
sanju09 wrote:Is |p| = q - r?
(1) p + q = r.
(2) p < 0.
using 1 alone,
p = r - q so not sufficient

using 2 alone,
p r q relation is not known.

uisng both
if p < 0, |p| = -p so,
|p| ≠ q - r so, sufficient .. Answer is C
Top
User avatar
Master | Next Rank: 500 Posts
Posts: 214
Joined: Mon Mar 29, 2010 1:46 pm
Location: Houston, TX
Thanked: 37 times
GMAT Score:700

by sk818020 » Tue May 18, 2010 8:41 am
(1) p+q=r, rewritten is;

p=q-r

Both side have to be positive or negative. It can't be that both sides have opposite signs. Thus,

If q-r is negative, lpl does not equal q-r.

If q-r is postive, then lpl=q-r.

Thus, (1) insufficient.

(2) p<0. This doesn't say anything about q or r. Thus, (2) insufficent.

Put them together, because p<0, q-r must also be negative. Thus lpl does not equal q-r. Thus,

IMO the answer is C.

What is the OA?
Top
Senior | Next Rank: 100 Posts
Posts: 50
Joined: Tue Oct 13, 2009 1:25 am
Thanked: 14 times
GMAT Score:720

by November Rain » Tue May 18, 2010 9:40 am
IMO A

If |p| = q - r it means that either p = q - r or (-p) = q - r

Statement 1 tell us that p + q = r -> p = r - q -> - p = q - r

Sufficient.


Statment B does not tell us anything. Insufficient
Top
User avatar
Master | Next Rank: 500 Posts
Posts: 214
Joined: Mon Mar 29, 2010 1:46 pm
Location: Houston, TX
Thanked: 37 times
GMAT Score:700

by sk818020 » Tue May 18, 2010 9:49 am
November Rain wrote:IMO A

If |p| = q - r it means that either p = q - r or (-p) = q - r

Statement 1 tell us that p + q = r -> p = r - q -> - p = q - r

Sufficient.


Statment B does not tell us anything. Insufficient
(1) is not sufficient because what if r-q is negative? It couldn't possibly be equal lpl. (1) does not tell us that r-q is not negative. It tells us it is equal to p. P could be negative. Therefore, r-q could be negative, at which point r-q could not equal an absolute value because absolute values are always positive.
Top
Junior | Next Rank: 30 Posts
Posts: 20
Joined: Wed Feb 25, 2009 9:59 pm
Thanked: 1 times
Followed by:1 members
GMAT Score:730

by thinkpanther » Tue May 18, 2010 10:25 am
IMO C


1) p + q = r

p = r-q

by definition of absolute value

when p is +ve |p| = p and when p is -ve |p| = -p

so insufficient

2) p <0 insufficient

combined:

|p| = -p = q-r hence sufficient
Top
Senior | Next Rank: 100 Posts
Posts: 50
Joined: Tue Oct 13, 2009 1:25 am
Thanked: 14 times
GMAT Score:720

by November Rain » Tue May 18, 2010 10:36 am
IMO A

If |p| = q - r it means that either p = q - r or (-p) = q - r

Statement 1 tell us that p + q = r -> p = r - q -> - p = q - r

Sufficient.


Statment B does not tell us anything. Insufficient
(1) is not sufficient because what if r-q is negative? It couldn't possibly be equal lpl. (1) does not tell us that r-q is not negative. It tells us it is equal to p. P could be negative. Therefore, r-q could be negative, at which point r-q could not equal an absolute value because absolute values are always positive.
Yes, you're right. I missed that possibility.
Top
User avatar
Master | Next Rank: 500 Posts
Posts: 318
Joined: Mon Jul 13, 2009 3:55 am
Thanked: 12 times

by nikhilkatira » Sun Jun 27, 2010 12:39 am
What is the OA ?
Best,
Nikhil H. Katira
Top
User avatar
GMAT Instructor
Posts: 3650
Joined: Wed Jan 21, 2009 4:27 am
Location: India
Thanked: 267 times
Followed by:80 members
GMAT Score:760

by sanju09 » Mon Jun 28, 2010 1:32 am
nikhilkatira wrote:What is the OA ?

When each statement alone is not clicking, we then take p = r - q, which is negative, cannot equal an absolute value; but q - r could.

[spoiler]C the OA[/spoiler]
The mind is everything. What you think you become. -Lord Buddha



Sanjeev K Saxena
Quantitative Instructor
The Princeton Review - Manya Abroad
Lucknow-226001

www.manyagroup.com
Top
Post new topic Post Reply
• Page 1 of 1