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

Redeem

gmatprep question

This topic has expert replies
Post new topic Post Reply
Previous Topic Next Topic
Junior | Next Rank: 30 Posts
Posts: 25
Joined: Sat Mar 27, 2010 9:00 am

gmatprep question

by JGaynor » Sun Apr 04, 2010 1:56 pm
I couldn't find this in the forum...

Is xy + xz = 0

1) x=0
2) y + z = 0

I know that statement is sufficient. But statement 2 could have y= -1 and z = 1 to equal zero but we don't know the value of x..??

Any insight on why statement 2 is sufficient here will be appreciated!

Thank you,

Jason
Top
Source: — Data Sufficiency |
Master | Next Rank: 500 Posts
Posts: 216
Joined: Mon Dec 21, 2009 10:26 am
Thanked: 16 times

by student22 » Sun Apr 04, 2010 2:17 pm
Factor xy + xz = 0 into x(y + z) = 0.

Statement 1:
x = 0, so 0 * (y + z) = 0. Sufficient.

Statement 2:
y + z = 0, so x * (0) = 0. Sufficient.

I hope this answers your question, when you factor the problem like this, you don't need to know the value of x for statement 2.
Top
User avatar
Master | Next Rank: 500 Posts
Posts: 435
Joined: Mon Mar 15, 2010 6:15 am
Thanked: 32 times
Followed by:1 members

by eaakbari » Sun Apr 04, 2010 8:39 pm
Stem:


xy+xz = 0
x(y+z)=0
So statement is 0 if x=0 or
y+z = 0 i.e y=-z

Statement One
Suff
So is 2nd statement

Hence D
Top
Post new topic Post Reply
• Page 1 of 1