X,Y,Z,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 odd
c)w must even
d)z must odd

• ans:a)w must be odd
  If X is even number then (y-z) must be even because even-even = always even.
  thus for (y-z-w) to be odd w must be odd. since,even-odd= always odd.
• 11 years agoHelpfull: Yes(33) No(5)
• W must be ODD.........
• 11 years agoHelpfull: Yes(5) No(4)
• option- A (must be odd)
  
  rules:
  o+o=even
  e-o=odd
  e-e= even
  and so on...
  from the expression X-Y-Z=even where X is even it means (Y-Z)must be even then only given expression will satisfy.
  
  From Y-Z-W= odd, it's only possible when W is odd.
• 11 years agoHelpfull: Yes(5) No(1)
• x-y-z=even and x is even then (y+z)=even; means either both are even or both are odd
  for that y-z is always even
  if y-z-w=odd theen w must be odd
  w is odd
• 11 years agoHelpfull: Yes(2) No(2)
• x is even so in 1st expression both x and y will both be either even or odd.
  now putting both in 2nd expression which holds only true when w must be odd so option (a) is correct.
• 11 years agoHelpfull: Yes(1) No(1)
• a) w must be odd
  
• 11 years agoHelpfull: Yes(1) No(2)
• W must b odd
• 11 years agoHelpfull: Yes(1) No(1)
• w must be odd.
• 11 years agoHelpfull: Yes(1) No(0)
• w must be odd
• 11 years agoHelpfull: Yes(1) No(0)
• 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 ans:a
  
• 11 years agoHelpfull: Yes(0) No(1)
• w must even
• 8 years agoHelpfull: Yes(0) No(0)