# Can anyone do Linear Programming???

Found 29th Oct 2010

Hi. Im doing linear programming at university and im really struggling.

I cant figure out a problem for one of my assignments and its doing my head in!! If you are good at LP then please let me know and I will post my assignment online.

Please Help!!

I cant figure out a problem for one of my assignments and its doing my head in!! If you are good at LP then please let me know and I will post my assignment online.

Please Help!!

Edited by:"JonnyTwoToes" 29th Oct 2010It is a long shot but I am desperate!!

A linear function to be maximized

e.g., Maximize: c1x1 + c2x2

Problem constraints of the following form

e.g.,

a1,1x1 + a1,2x2 ≤ b1

a2,1x1 + a2,2x2 ≤ b2

a3,1x1 + a3,2x2 ≤ b3

Non-negative variables

e.g.,

x1 ≥ 0

x2 ≥ 0.

Non-negative right hand side constants

bi ≥ 0

The problem is usually expressed in matrix form, and then becomes:

Maximize: cTx

Subject to: Ax ≤ b, x ≥ 0.

The Good-to-Go suitcase company makes three kinds of suitcases: (1) Standard, (2) Deluxe, and (3) Luxury styles. All the relevant information on the making of the suitcases and associated costs are tabulated in the Excel worksheet.

(a) You must solve the problem to find the optimal production plan.

(b) Suppose Good-to-Go is considering including a polishing process, the cost of which would be reflected in the price. The table below supplies the time needed for polishing for each type of suitcase:

Suitcase Polishing time (minutes)

Standard 10

Deluxe 15

Luxury 20

An additional 170 hours of polishing time are available. You must solve the new problem to find the optimal production plan.

(c) Next consider the addition of a waterproofing process with the relevant data below:

Suitcase Waterproofing (hours)

Standard 1

Deluxe 1.5

Luxury 1.75

An additional 900 hours of waterproofing time are available. You must solve the new problem to find the optimal production plan.

(d) Good-to-Go is considering the possible introduction of two new products to its line: the Compact model (for teenagers) and the Kiddo model (for children). Market research suggests that Good-to-Go can sell the Compact model for £30 and the Kiddo model for £37.50. The amount of labour and cost of raw materials for each new product are as follows:

Cost category per unit Compact Kiddo

Cutting and colouring (hours) 0.50 1.20

Assembly (hours) 0.75 0.75

Finishing (hours) 0.75 0.50

Quality and packaging (hours) 0.20 0.20

Raw materials (£) 5 4.50

Neither polishing nor waterproofing is to be considered for (d). You must determine whether either new model is worth making.

Standard Deluxe Luxury

Decision variables

Selling price per unit (£) 36.05 39.50 43.30

Material cost per unit (£) 6.25 7.50 8.50

Labour cost per unit (£) 15.48 18.67 21.26

Constraints (hours per unit) Total Hours Limit Labour cost per hour (£)

Cutting and colouring 0.7 1 1 <= 630 10

Assembly 0.5 0.83 0.67 <= 600 6

Finishing 1 0.67 0.9 <= 708 9

Quality and packaging 0.1 0.25 0.4 <= 135 8

Thats all the info I have!!! Knock yourselves out

LHS Sign RHS

Not sure I fully understood it, but the example we used was for making a Museli with all the different ingredients - nuts, raisins, bran etc.

Each component had a cost (nuts are more expensive than raisins for example) so you looked at all the ingrediants and worked out how much of each you could use to give a desired cost to sell the product and still make a profit.

Edited by:"guilbert53" 29th Oct 2010youtube.com/wat…_n8

+1 - on the maths section or something (assuming they have a maths section lol)

I came into the thread thinking it was something to do with computer programming. Could have maybe helped with that but this looks hard! The Wikipedia page only complicates things!