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A certain list consists several integers

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ekattur
 Post subject: A certain list consists several integers
 Post Posted: Mon Feb 16, 2009 10:57 pm 
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Course Students


Posts: 2
A certain list contains several different integers. Is the product of the integers in the list positive?

1) The product of the greatest and the smallest of the integers in the list is positive
2) There is an even number of integers in the list

OA is C, I had selected E thinking that 0 could be in the list and hence we don't know.

Can anyone please explain where I went wrong? Thanks
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RonPurewal
 Post subject: Re: A certain list consists several integers
 Post Posted: Wed Feb 18, 2009 6:44 am 
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ManhattanGMAT Staff


Posts: 7146
ekattur wrote:
OA is C, I had selected E thinking that 0 could be in the list and hence we don't know.


nope.

statement (1) means that the smallest and largest elements of the list have the same sign, i.e., are both positive or both negative.
but, since those are the smallest and largest elements of the list, that means that all the elements between have to have that same sign, too.
or:
you can't have 0 between two positive numbers, or between two negative numbers.
either everything in the list is positive, or everything in the list is negative.
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ekattur
 Post subject: Re: A certain list consists several integers
 Post Posted: Wed Feb 18, 2009 11:42 am 
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Course Students


Posts: 2
RonPurewal wrote:
ekattur wrote:
OA is C, I had selected E thinking that 0 could be in the list and hence we don't know.


nope.

statement (1) means that the smallest and largest elements of the list have the same sign, i.e., are both positive or both negative.
but, since those are the smallest and largest elements of the list, that means that all the elements between have to have that same sign, too.
or:
you can't have 0 between two positive numbers, or between two negative numbers.
either everything in the list is positive, or everything in the list is negative.


Thanks Ron!
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JonathanSchneider
 Post subject: Re: A certain list consists several integers
 Post Posted: Thu Feb 19, 2009 4:12 pm 
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ManhattanGMAT Staff


Posts: 480
Location: Durham, NC
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