If (x+y)/z < 0, is x <0? (1) x<y (2)z<0

This topic has expert replies
User avatar
Legendary Member
Posts: 626
Joined: Fri Dec 23, 2011 2:50 am
Location: Ahmedabad
Thanked: 31 times
Followed by:10 members

by ronnie1985 » Thu Jan 05, 2012 1:11 am
S1. Insufficient as nothing is said of z and y
S2. x+y>0 is the implication, sign of x cannot be ascertained.
S1 and S2 combined also, sign of x cannot be ascertained. Hence (E) is answer.
Follow your passion, Success as perceived by others shall follow you

Master | Next Rank: 500 Posts
Posts: 382
Joined: Thu Mar 31, 2011 5:47 pm
Thanked: 15 times

by ArunangsuSahu » Thu Jan 05, 2012 9:01 am
One Common mistake to avoid don't multiply z to 0 without knowing the nature of 'z'

Statement 1:
x < y

a) x can be +ive,0 or -ive
b) z is unknown
z can be less than 0. In that case (x+y) < 0. or x<-y.This satisfies as x<y and x<-y both takes x to negative direction.
z can be greater than 0. In that case (x+y) < 0 or x<-y.Doesn't satisfy the Given data is Statement1 .

So INSUFFICIENT

Statement 2:
z < 0.

In that case (x+y) < 0. or x<-y.
y is unknown
x= 2, y= -3..x>0
x=-3, y=-2..x<0

INSUFFICIENT

Combining (1) and (2)
we get the intersection
This satisfies as x<y and x<-y both takes x to negative direction.
a)x<y
b)x<-y

Senior | Next Rank: 100 Posts
Posts: 95
Joined: Wed Feb 09, 2011 6:42 am
Thanked: 1 times
Followed by:1 members

by singalong » Fri Jan 13, 2012 7:11 pm
ArunangsuSahu wrote:One Common mistake to avoid don't multiply z to 0 without knowing the nature of 'z'

Statement 1:
x < y

b) z is unknown
z can be less than 0. In that case (x+y) < 0. or x<-y.This satisfies as x<y and x<-y both takes x to negative direction.
z can be greater than 0. In that case (x+y) < 0 or x<-y.Doesn't satisfy the Given data is Statement1 .
If z is greater than zero, how is (x+y)_< 0 ? shouldn't it be (x+y) > 0?

User avatar
Legendary Member
Posts: 934
Joined: Tue Nov 09, 2010 5:16 am
Location: AAMCHI MUMBAI LOCAL
Thanked: 63 times
Followed by:14 members

by [email protected] » Thu Jan 19, 2012 11:11 pm
The correct answer is E if the sign given is less than 0

The correct answer is C if the sign given is greater than 0

Yes, the inequality was a good one...
IT IS TIME TO BEAT THE GMAT

LEARNING, APPLICATION AND TIMING IS THE FACT OF GMAT AND LIFE AS WELL... KEEP PLAYING!!!

Whenever you feel that my post really helped you to learn something new, please press on the 'THANK' button.