if x and y are real number. x+y is even?
a - x-y id odd
b - x^2 - y^2 is odd

options are like elitmus

• x-y=odd.
  This means x=even, y=odd or y=even, x=odd.
  so x+y=even + odd=odd.
  
  x^2-y^2=odd
  now,
  x^2-y^2=(x-y)(x+y)
  Its only possible when both (x-y) , (x+y) are odd so as to make the product odd.
  
  Take, for example, 5 and 2.
  5-2=3;
  25-4=21.
  So, either of the two statements can answer the question.
  
• 8 years agoHelpfull: Yes(20) No(4)
• Both options are wrong.
  
  If x+y is even that means that either both x and y are even or both are odd.
  
  suppose
  (i) even numbers are 4 & 2
  so x-y = 4-2 = 2 i.e. not odd
  and 4^2 - 2^2 is also not odd
  (ii) odd numbers are 5 & 3
  5-3 = 2 is not odd
  and 5^2 - 3^2 = 16 i.e. not odd
  
  hence, both the answers are wrong
  
• 8 years agoHelpfull: Yes(6) No(13)
• can be answered by either of the statement
  from a) and b) v cud conclude that x is even and y is odd ( use hit and trial)
  therefore x+y is always odd hence the possible answer is NO, x+y is not even
• 8 years agoHelpfull: Yes(2) No(2)
• It can be answer by using option A : x-y is odd.
• 8 years agoHelpfull: Yes(2) No(3)
• everyone here is getting to the wrong answer by assuming the no. as whole number while the question clearly states that x and y are real numbers
  
  if we take x=7/2 and y= 1/2
  then x-y = 7/2-1/2 = 3 which is odd,
  but (7/2)^2-(1/2)^2 = 49/4 - 1/4 = 12 which is even
  so both statements together draw the conclusion that no. should be taken as whole no. which satisfy the above two conditions i.e. one even and other odd.
  hence, both statements are necessary
• 7 years agoHelpfull: Yes(2) No(1)
• Both the options are wrong
  
• 8 years agoHelpfull: Yes(1) No(4)
• neither option a nor b is right
• 8 years agoHelpfull: Yes(1) No(2)
• Both r wrong
• 8 years agoHelpfull: Yes(1) No(1)
• Hey y are u guys telling both option option are wrong .question is not about option it's about statement it's asking that is x+y is even so both are saying no means both are sufficient alone. Its not about X+y sud be even its just asking yes or no . So in any case ans is sufficient if its ans is maybe then i tll be not sufficient
• 7 years agoHelpfull: Yes(1) No(0)
• If x+y ,then x and y should be both even or both odd
  X-y cannot be odd
  x^2-y^2 cannot be odd
  So both are wrong
• 8 years agoHelpfull: Yes(0) No(0)
• neither option A nor option B
• 8 years agoHelpfull: Yes(0) No(0)