Is the product ny greater than 0 ? (1) n is between –1 and 1. (2) y

Answer E

N and y can be positive, zero,integer,non- integer.


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Hi taniad
I would like to help you out with this question

Is the product ny greater than 0 ?

(1) n is between –1 and 1.
(2) y is between –5 and 5.

Statement 1 Only value of n is given which can be positive as well as negative , y can be positive/negative or even 0 . So the product ny can be less than/greater than or even greater than 0 considering multiple scenarios/ So Statement 1 alone is not suffice

Statement 2 Only value of y is given which can be positive as well as negative , n can be positive/negative or even 0 . So the product ny can be less than/greater than or even greater than 0 considering multiple scenarios. So Statement 2 alone is not suffice

Now when we combine both statements 1 and 2, still we cannot arrive at a definite answer
1) If both n and y are 0 or even either of n and y are 0 entire product will be 0, so the answer would be No
2) If n is positive and y is negative and vice versa, product will be negative, so the answer would be No
3) If both n and y are negative or positive, then product ny shall be greater than 0 and answer shall be Yes

So in the 3 scenarios we are not getting a definite answer

Hence both the statements together are also not suffice and answer is E

N is between -1 and 1, does this mean N=0?

If N is an integer, yes but we do not know that, so N can be any number from -1 to 1, say -3/4, -1/9, 11/19, ...
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EducationAisle GMATBusters when we say n is between -1 and 1 does it mean -1 ≤ n ≤ 1 OR does it mean 1 < n < 1? In other words, is -1 and 1 INCLUSIVE?

If n is between a and b (where a <b)
it means a<n<b

end points are NOT inclusive.


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Experts -

Would a good approach be to test vales for this problem? I tested the extremes at first but then realized it is asking for between the extremes.
E.g., I did the following:

let n= -1/2 and let y= -4 so ny=2 --> yes >0

let n=-1/2 and let y=4 so ny= -2--> no

let n=1/2 and let y=-4 so ny= -2--> no

let n=1/2 and let y= 4 so ny=2--> yes>0

Clearly insufficient bc. you get yes and no for different sets of values.