Numbers in the list

[crackgmat007]

OA - B Why not A

[raghavsarathy]

Consider the set with elements {2, 0 , 0} In this case , the product of any two numbers is 0 but not every element is 0. Hence A is insufficient.

[mehravikas]

Question says there are no more than 2 numbers in the list..

so the list can also be {2, -2} or {0, 0}

So how is statement B sufficient?

Consider the set with elements {2, 0 , 0} In this case , the product of any two numbers is 0 but not every element is 0. Hence A is insufficient.

[pandeyvineet24]

Its a Yes/No question.

Actually B is suefficient because it says that sum of any 2 numbers is always 0. This can only happen if all the numbers are 0's in the set.
It does not work for any other set of numbers.

lets try (2,-2,2,-2,..) sum of 2 & -2 is 0, but not sum of 2 & 2 or -2 & -2.

[mehravikas]

Damn...I read the question as "no more than 2 numbers in the list"

Got it wrong.

Its a Yes/No question.

Actually B is suefficient because it says that sum of any 2 numbers is always 0. This can only happen if all the numbers are 0's in the set.
It does not work for any other set of numbers.

lets try (2,-2,2,-2,..) sum of 2 & -2 is 0, but not sum of 2 & 2 or -2 & -2.