The rate order is
2X + Y → Z
which is correct:
_1_ order with respect to [X] and _0_ order with respect to [Y]. The overall rate order is _1_.
_0_ order with respect to [X] and _1_ order with respect to [Y]. The overall rate order is _1_.
_1_ order with respect to [X] and _1_ order with respect to [Y]. The overall rate order is _1_.
_1_ order with respect to [X] and _1_ order with respect to [Y]. The overall rate order is _2_.