if X and Y are integers, is X even? 1) X^2-Y^2=0 2)

Question

if X and Y are integers, is X even? 

1) X^2-Y^2=0 

2) X^2+Y^2=18

Dilshod · Answer

Hi,
it is B
st 1 is clearly insuff.
st2 only 3 for both x and y satsfies this statement. Suff.

Dilshod · Answer

ups...thought y is also integer.

It is C

rnachloo · Answer

I think it is 'B'. The question does say X and Y are integers. Am I missing anything?

u2lover · Answer

1) x could be even or odd and so is y, but one of them must be negative, so we don't know

2) x+y=even, so o+o=e e+e=e, but o*o=o and e*e=e, which makes o+e=odd... we need both x and y to be both either even or odd... and since the sum is 18 they must both be odd.

B

ywilfred · Answer

St1:

(x+y)(x-y)=0

Just tells us |x|=|y| and x and y could be even or odd. Insufficient.

St2:
x^2+y^2=18

(x,y) can only be (3,3) if both x and y are integers --> x is odd. Sufficient.


Ans B

buzzgaurav · Answer

Late but B.
Statement 2 clearly suffices in deciding that both X and Y equal 3.

jaynayak · Answer

B.

1) Not Suff. X can be any number.
2) Only when x and y is 3 the equation is satisfied . Hence X is not even 
Suff

amit79 · Answer

1)this is not suff. as it could be any value:2 ,3 ,4...
2) here it will be either 3 or -3.

Ans is B

if X and Y are integers, is X even? 1) X^2-Y^2=0 2)

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