Is (x-y)*(x+y) an even integer?

Question

1)x and y are integers
2) x+y is even

OA  C

agdimple333 · Answer

hi can you correct your st-1

agdimple333 · Answer

if your statement 1 means x and y are integers than

st-1 ==> not sufficient. x and y could be integer like x = 4 and y = 1 then (x+y)*(x-y) is odd integer and x =4 and y =2 makes the expression even integer
st-2 ==>not sufficient; x+y just says even... we dont know if its integer.like x = 4 and y=0.2 then (x+y) * (x-y) is even number (but not integer) and x=4 and y=2 makes the expression even integer.

together we know x and y are integers and x+y is even so the exp wil be even integer.

fluke · Answer

Set and question number?

amit2k9 · Answer

a x and y can both be either even or odd giving different values. x,y = 2,4 or 5,2. Not sufficient.

b x=1.6 y = 0.4 giving non integer value for the equation. Not sufficient.

a+b x and y have to be either both even or odd integers.

C it is.

cvsmech · Answer

AD/BCE

Statement 1 is not sufficient by itself therefore neither A nor D could be the answer.

Statement 2 is not sufficient if we don't know if they are integers or not.

If used together, (x+y) = even implies that either x and y are both even or both odd.

Therefore, x-y = even as well. Which implies their product has to be even. Hence option c.

Is (x-y)*(x+y) an even integer?

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