I tried every thing you said, but it still doesn't work. So I will submit it to Maplesoft Support.

Thanks for all your help.

Mario

I tried again. With different initial points. And Maple stils don't give me the answer.

Using infolevel I got this:

> with(Optimization);
> infolevel[Optimization] := 3;
                                      3
Maximize(40*a+60*b, {40*a+60*b <= 150}, assume = nonnegint, initialpoint = [a = 1, b = 1], depthlimit = 10);

LPSolve: calling ILP solver
SolveInteger: number of problem variables 2
SolveInteger: number of general linear constraints 1
PrintSettings: feasibility tolerance set to 0.1053671213e-7
PrintSettings: integer tolerance set to 0.10e-4
PrintSettings: infinite bound set to 0.10e21
PrintSettings: iteration limit set to 50
PrintSettings: depth limit set to 10
PrintSettings: node limit set to 0
Warning, problem appears to be unbounded
                            [100, [a = 1, b = 1]]
 

I modified all parameters, and nothing helps. Any other ideia?

Really Thanks!

Mario

Windows XP SP2, Maple 11.02.

And all other specifications are above the recomended for Maple 11.

Mario

That is not a perfect solution, but maybe it's the only one. But a asked a friend to do it in Maple 11, he runs Maple on Ubuntu 8.04. And there it worked.

So it likes that the problem is with my computer configuration, I don't know. Is that possible?

Mario

Thanks for answering, but I tried in Maple 11 increasing depthlimit, but it still doesn't work. Could it be something from my computer? Because I use Maple 11 here, and Maple 10 in the university, and there the comand works, here it doesn't.

(I copied the comand on Maple, and I'm putting here what happened when I tried)

> with(Optimization);

Maximize(40*a+60*b, {40*a+60*b <= 150}, assume = nonnegint, depthlimit = 10);

Warning, problem appears to be unbounded
                             [0, [a = 0, b = 0]]
 

Mario