Hello everyone

I created the following program or whatever you call it and compile it with no error, however I got zeros in my z solution

Positive variable x1, x2, x3;

free variable z;

Equations

Con1,

Con2,

Con3,

Obj;

;

Con1.. 75*x1 + 131*x2 + 169*x3 =L= 375;

Con2.. 9*x1 + 15*x2 + 20*x3 =L= 44;

Con3.. 7*x1 + 12*x2 + 15*x3 =L= 34;

Obj.. 0.2*x1 + 0.3*x2+ 0.5*x3 =E= z;

Model Time_minimization /

Con1,

Con2,

Con3,

Obj / ;

options lp = cplex;

Solve Time_minimization Using lp Minimizing z;

Display x1.L, x2.L, x3.L, z.L;

can anyone tell me what's wrong with it????

## Please help with solver

### Re: Please help with solver

Hi

There is nothing wrong with your solution: you have three less-than-or-equal constraints and a to minimize objective equation all with positive coefficients.

This means that {0,0,0} is the minimal and optimal solution. All constraints are met and the objective variable is minimized.

Perhaps you meant greater-than-or-equal in your constraints.

Cheers

Renger

There is nothing wrong with your solution: you have three less-than-or-equal constraints and a to minimize objective equation all with positive coefficients.

This means that {0,0,0} is the minimal and optimal solution. All constraints are met and the objective variable is minimized.

Perhaps you meant greater-than-or-equal in your constraints.

Cheers

Renger

____________________________________

Enjoy modeling even more: The lazy economist

Enjoy modeling even more: The lazy economist

### Re: Please help with solver

thanks for reply first of allRenger wrote: ↑6 months agoHi

There is nothing wrong with your solution: you have three less-than-or-equal constraints and a to minimize objective equation all with positive coefficients.

This means that {0,0,0} is the minimal and optimal solution. All constraints are met and the objective variable is minimized.

Perhaps you meant greater-than-or-equal in your constraints.

Cheers

Renger

I go zeros for solution, what should I do to get optimal numbers for the three unknowns??

### Re: Please help with solver

Hi

This is the optimal solution imagine a one-dimensional problem: x<5 and z=3x. 0 is the optimal solution.

It would make more sense if you would have >= constraints.

Cheers

Renger

This is the optimal solution imagine a one-dimensional problem: x<5 and z=3x. 0 is the optimal solution.

It would make more sense if you would have >= constraints.

Cheers

Renger

____________________________________

Enjoy modeling even more: The lazy economist

Enjoy modeling even more: The lazy economist