X, Y, X and W are integers. The expression X - Y - Z is even and the expression Y - Z - W is odd. If X is even what must be true?
a) W must be odd
b) Y - Z must be odd
c) W must be odd
d) Z must be odd

• c. w must be odd
  as we know even-even=even,odd-odd=even,even-odd=odd
  since in expression x-y-z,x is even therefore y-z must be even
  in expression y-z-w,y-z is even(we calculate it earlier) hence w must be an odd to satisfy the 2nd expression
• 11 years agoHelpfull: Yes(22) No(1)
• A.W must be odd
• 11 years agoHelpfull: Yes(2) No(2)
• A. W must be odd
• 11 years agoHelpfull: Yes(2) No(0)
• w must be odd otherwise 2nd expression will not be odd
• 11 years agoHelpfull: Yes(1) No(1)
• y-z must be odd
• 11 years agoHelpfull: Yes(1) No(4)
• there are many mistakes in que
  
• 11 years agoHelpfull: Yes(0) No(1)
• A. W must be odd
• 11 years agoHelpfull: Yes(0) No(0)
• w must be odd
• 11 years agoHelpfull: Yes(0) No(0)
• w must be odd bcoz y+z is even
• 11 years agoHelpfull: Yes(0) No(1)
• a.w must be odd
• 11 years agoHelpfull: Yes(0) No(0)
• w must be odd because if x is even y-z should be even to satisfy x-y-z to be true therfore w should be odd to satisfy y-z-w
• 11 years agoHelpfull: Yes(0) No(0)
• given expression=x-y-z=even
  again y-z-w=odd
  now add both we get
  x-y-z+(y-z-w)=x-w
  and according to questions x is even so;
  even -w=odd
  so to get we have to subtract odd so w must be odd.answer A and B both are same.
• 11 years agoHelpfull: Yes(0) No(0)
• to all those who say answwer is w is odd...take x=13 y=7 z=4 w=2 .... now check..eq holds true even if w is even...answer is none of these
• 11 years agoHelpfull: Yes(0) No(0)
• x is even
  so take y,z values are 2,4
  so x-y-z=8-2-4=2 even value
  x=8
  y-z-w=odd
  but y,z is even value
  any even value add and sub same even value should come
  so w is odd integer
• 11 years agoHelpfull: Yes(0) No(0)