if x, y and z are integers, is x+y+2z even?
A. x + z is even
B.y + z is even
Various approaches,please!
A. x + z is even
B.y + z is even
Various approaches,please!
is x+y+2z even?
A. x+y is even
2 combinations:-
1. e+e = e
2. o+o = e
2z is always going to be even. x+y is even. So, x+y+2z is always even. Sufficient.
B. y+z is even
Either both y and z are odd OR both y and z are even.
Assume y and z are odd, 2z is always even.
If x is odd and y is odd, x+y is even. So, x+y+2z is even.
If x is even and y is odd, x+y is odd. So, x+y+2z is odd.
Insufficient.
A
NOTE: Please attach the OA in a spoiler.
