Solving a linear programming problem using the simplex algorithm may give non integer solutions. Such solutions may not be practical, and we must look for integer solutions for each variable. The process of looking for integer solutions is called vertex testing. Suppose we have solved the linear programming problem:
Maximise subject to the constraints
subject to the constraints and
and
The simplex algorithm returns the solution

These are non integer solutions but we require integer solutions. We must test integer values of and
 and close to the solution above, to ensure that they satisfy the constraints and return a maximum value of
close to the solution above, to ensure that they satisfy the constraints and return a maximum value of
The points to test are
| Point | 
 | 
 | Satisfies constraints? | Value | 
| 
 | 2*12+3*3=33 | 4*12+3*3=57 | yes | 12+3=15 | 
| 
 | 2*12+3*4=36 | 4*12+3*4=60 | No | 12+4=16 | 
| 
 | 2*13+3*3=35 | 4*13+3*3=61 | No | 13+3=16 | 
| 
 | 2*13+3*4=38 | 4*13+3*4=64 | No | 13+4=17 | 
The only one of these points which satisfies the constraints is so the solution is
so the solution is and
and  and the value of
and the value of is 15.
is 15.




