I have an integer programming problem that I formulated in excel. My problem is as below and I do not know what is wrong:
For example we have $30$ hours of available time. It takes $2$ hours to assembly a phone, $4$ hours for a PC and $3$ hours for a TV. After adding all such constraints, I want to maximize total profit. The solver can not find a convergent solution. However, if I say set objective value to $1000$ dollars when profit per a phone is $25$ dollars for example, it finds a solution like $40$-many phones and none of any other product. The problem is, that should not be possible since it will take $40\times2 = 80$ hours of assembly time.
What may be the problem? I am out of ideas. Thank you.