inequalities - numbers

This topic has expert replies
Junior | Next Rank: 30 Posts
Posts: 23
Joined: Sun Sep 07, 2008 7:22 am
Location: India
Thanked: 4 times
GMAT Score:700

inequalities - numbers

by uttara » Mon Oct 27, 2008 8:56 am
If n & p are integers, is p>0?

(1) n+1>0
(2) np>0

Legendary Member
Posts: 1153
Joined: Wed Jun 20, 2007 6:21 am
Thanked: 146 times
Followed by:2 members

Re: inequalities - numbers

by parallel_chase » Mon Oct 27, 2008 9:36 am
uttara wrote:If n & p are integers, is p>0?

(1) n+1>0
(2) np>0
Statement I

n+1 >0
n>-1, we dont know anything about p. Insufficient.

Statement II
np>0

n and p both can be either positive or negative. Insufficient.

Combining I & II
n>-1
np>0

We know that n and p are both integers, n can be either 0 or greater than 0, since np>0, n cannot be 0. Therefore, n>0 and p>0.

Hence C.

OA?
Last edited by parallel_chase on Mon Oct 27, 2008 9:37 am, edited 1 time in total.
No rest for the Wicked....

User avatar
Legendary Member
Posts: 2134
Joined: Mon Oct 20, 2008 11:26 pm
Thanked: 237 times
Followed by:25 members
GMAT Score:730

by logitech » Mon Oct 27, 2008 9:37 am
If n & p are integers, is p>0?

(1) n+1>0
(2) np>0

(1) Insuf - there is nothing about P so you can eliminate A and D

(2) Insuf - we dont know whether N is negative or positive they can be both + or both - , you can eliminate B as well

so it is either C or E

(1) + (2) - well n & p are integers and n > -1 which means N can be 0, 1, 2, .... ( positive )

and if np>0 than P needs to be + so IMO it is C

But they were not INTEGERS, N could be negative too so E would had been the answer.

and what is OA ?
LGTCH
---------------------
"DON'T LET ANYONE STEAL YOUR DREAM!"

Junior | Next Rank: 30 Posts
Posts: 23
Joined: Sun Sep 07, 2008 7:22 am
Location: India
Thanked: 4 times
GMAT Score:700

by uttara » Mon Oct 27, 2008 10:00 am
Thanks guys

OA is C


i had answered it as E earlier. Now i realize i had forgotten to read integers in If n & p are integers, is p>0? :lol: :lol: