onsider the following integer linear programming problem:

MaxZ$=,31+22$

Subject to: $31+5230$

$41+2228$

$x18$

$x1,x20$ and integer

What is the optimal solution to the integer linear programming problem?

none of these

$x1=5\mathrm{.}714,x^{}2=2\mathrm{.}571,Z=22\mathrm{.}286$

$x1=2,x2=6,Z=18$

$x1=6,x2=2,Z=22$