MathCAD



Picture 3.11. The problem about paint - 2


First of all if we change the initial installation of Solver the problem about paint can be right explained by the Solver of Excel. For it we could not be lazy and had to press the button Parameters in the dialogue window Search of the

solution. In new dialogue window Parameters of the search of the solution

it was enough to decrease the admissible deviation from 5 to 1%. After it the right solution was found (15 big and 6 small drums). Frankly speaking in Excel Solver is not bad, but its initial installations are. There are few users Excel who apply Solver and press the button Parameters

But who understand the heart of the problem of the optimizations installations does not work with Excel. One gets some misunderstandings because of it.

In the second place both Olga and Excel, and Mathcad in different degree were disappointed me a little[10]: 910 litres of the paint could be packed another way-13 small and the same quality big drums[11]. In this case the balance was only 12 thousand roubles. And what is more the solution of the problem about paint with new criterion function (worth of paint in the drums) gives one more result: 37 small and 6 big drums. This way we get one thousand roubles else from Tambov-power.

Version of packing (quantity of small drums/quantity of big drums)

2/16

6/15

13/13

37/6

Volume of paint (litres)

910

915

910

885

The rest of money (roubles)

186 000

47 000

12 000

11 000

In the third place when I showed this table in the supply department MPEI then I was told that the most optimum alternative both for me (money are important for me) and for MPEI (it needs paint) the fourth one: we get almost all money from Tambov-power. It seems strange but 885 litres of paint is more than 910 and 915. Point is that a lot of paint are lost because of tint from massive drums to small tare. The drum with 15 litres can be taken to the maintainable lecture hall and can be used completely.

The wrong solution is got not only because of bad methods or bad software, but because of user does not know exactly what he really wants. All programs of linear programmings solutions require the clear formulation of only one criterion function[12]. The purpose is clear when we solve training problems. What purpose do we have for in our life? But it is the mathematics but it is the philosophy