Data Sufficiency Problem on - Positive Negative Integers

This topic has expert replies
Newbie | Next Rank: 10 Posts
Posts: 3
Joined: Mon Mar 02, 2009 5:36 pm
Location: Chicago
Hi
I have a question- DS that I am unable to solve - needs your thoughts of this

Q: Is the product of all the elements of Set X negative
1. All the elements in Set X are negative
2. There are 5 negative numbers in set X.

How should I go about approaching this.

The solution in the guide has thrown me off a bit.
It says for point 2 - that this is insufficient because if any of the elements of the set x is 0 then the product is zero which is not negative.

However my point is - that if the statement itself says that there are 5 negative numbers in the set - how can you assume that one of the elements is 0.

Also - Does the statement - There are 5 negative numbers in the set X imply that there are exactly 5 elements in the set??

Please advice.
Thanks
Yogesh

Legendary Member
Posts: 2467
Joined: Thu Aug 28, 2008 6:14 pm
Thanked: 331 times
Followed by:11 members

by cramya » Mon Mar 02, 2009 6:08 pm
However my point is - that if the statement itself says that there are 5 negative numbers in the set - how can you assume that one of the elements is 0.

Also - Does the statement - There are 5 negative numbers in the set X imply that there are exactly 5 elements in the set

there are 5 negative numbers in the set means precisley that. There could be just 5 all of them being negative or any number of elements and we don't have a clue(all we know is 5 are negative).

There are 5 negative numbers in the set X imply that there are exactly 5 elements in the set-> No not necessarily as pointed out above.

Hope this helps!


Regards,
Cramya

Master | Next Rank: 500 Posts
Posts: 140
Joined: Sat Feb 28, 2009 8:51 am
Location: India
Thanked: 14 times
Followed by:3 members
Q: Is the product of all the elements of Set X negative
1. All the elements in Set X are negative
2. There are 5 negative numbers in set X.
Lets take Statement 1:

If all elements are negative, then product is negative?
Cannot determine. All elements are negative but no idea of total no. of elements. So answer AD is not possible.

Now take Statement 2:

5 negative numbers(odd times)...then product should be negative. But what happen, if one element is 0?

So option E is sufficient.
Regards,
Farooq Farooqui.
London. UK

It is your Attitude, not your Aptitude, that determines your Altitude.

Master | Next Rank: 500 Posts
Posts: 424
Joined: Sun Dec 07, 2008 5:15 pm
Location: Sydney
Thanked: 12 times
yogesh_jain wrote:Hi
I have a question- DS that I am unable to solve - needs your thoughts of this

Q: Is the product of all the elements of Set X negative
1. All the elements in Set X are negative
2. There are 5 negative numbers in set X.

How should I go about approaching this.

The solution in the guide has thrown me off a bit.
It says for point 2 - that this is insufficient because if any of the elements of the set x is 0 then the product is zero which is not negative.

However my point is - that if the statement itself says that there are 5 negative numbers in the set - how can you assume that one of the elements is 0.

Also - Does the statement - There are 5 negative numbers in the set X imply that there are exactly 5 elements in the set??

Please advice.
Thanks
Yogesh
So wats an OA??

C is it?

Senior | Next Rank: 100 Posts
Posts: 44
Joined: Tue Feb 03, 2009 5:17 am

by mridula » Tue Mar 03, 2009 11:40 am
Must be C.