x,y,z, and w are integers.the expression X-Y-Z is even and the expression Y-Z-Wis 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.
  
  given
  X-Y-Z is even and the expression Y-Z-W is odd.
  X is even , then Y and Z both are of same type i.e. even or odd.
  Then Y-Z is always even.
  But Y-Z-W is odd, so W must be odd.
  
  
• 12 years agoHelpfull: Yes(49) No(5)
• x-y-z=even;
  y-z-w=odd;
  even-odd=odd;
  x=even;
  add the above two statements we get;
  x-w=odd;
  so w=odd
• 12 years agoHelpfull: Yes(38) No(5)
• Z must odd beacause y-z-w is odd numbber.hence w must be 1,3,5 ,7, 9 etc
  
• 12 years agoHelpfull: Yes(4) No(16)
• Given, x-y-z=even
  then,y-z=result-x=even ..........(a) [as a even no-even no=even no...............here given x is an even no]
  In the 2nd expression given ,
  y-z-w=odd
  then ,even-w=odd.......[from (a)].........[as always even-add=odd]
  then ,ans(c) w must be an odd
• 10 years agoHelpfull: Yes(2) No(0)
• given x-y-z is even and x is odd so to get even from whole expression we consider y-z is odd,
  where both are even or odd
  next y-z-w ,
  y-z is always even.
  but y-z-w is odd so w must be odd.
• 8 years agoHelpfull: Yes(0) No(0)
• Options A and C are the same w must be odd.
  
  given
  X-Y-Z is even and the expression Y-Z-W is odd.
  X is even , then Y and Z both are of same type i.e. even or odd.
  Then Y-Z is always even.
  But Y-Z-W is odd, so W must be odd
• 8 years agoHelpfull: Yes(0) No(0)