An oil fired power station burns three grades of oil: grade A, grade B and grade C.
The efficiency with which electricity can be produced from the burning of these oils
depends upon the presence of three ingredients: X, Y and Z which are known to be
present in each ton of the three grades as shown in the table below:
Tons of ingredient per ton of oil
X Y Z
Grade A 0.2 0.4 0.3
Grade B 0.1 0.3 0.2
Grade C 0.3 0.2 0.4
Maximum efficiency in the burning process requires the presence of at least 200 tons
of ingredient X, at least 175 tons of ingredient Y, and at least 300 tons of ingredient
Z, in 1 hour of continuous electricity production.
The power station purchases the oil at prices of ?60, ?80, and ?70 per ton for grades
A, B and C respectively, and is required to operate for 12 hours per day.
Formulate the linear program which will minimize the total daily cost of
electricity production.

Can anyone help me with this one???

Thank you!

"Petros Papadopoulos" <petrosp13@yahoo.gr> wrote in message 
news:hfkpai$nam$1@fred.mathworks.com...
> An oil fired power station burns three grades of oil: grade A, grade B and 
> grade C.
> The efficiency with which electricity can be produced from the burning of 
> these oils
> depends upon the presence of three ingredients: X, Y and Z which are known 
> to be
> present in each ton of the three grades as shown in the table below:
> Tons of ingredient per ton of oil
> X Y Z
> Grade A 0.2 0.4 0.3
> Grade B 0.1 0.3 0.2
> Grade C 0.3 0.2 0.4
> Maximum efficiency in the burning process requires the presence of at 
> least 200 tons
> of ingredient X, at least 175 tons of ingredient Y, and at least 300 tons 
> of ingredient
> Z, in 1 hour of continuous electricity production.
> The power station purchases the oil at prices of ?60, ?80, and ?70 per ton 
> for grades
> A, B and C respectively, and is required to operate for 12 hours per day.
> Formulate the linear program which will minimize the total daily cost of
> electricity production.
>
> Can anyone help me with this one???

Use LINPROG.  The Wikipedia page for "Linear programming" includes an 
example that's similar to what you described that will show you how to 
transform the problem from text into matrices and vectors; once you have 
those, just call LINPROG.

http://en.wikipedia.org/wiki/Linear_programming

-- 
Steve Lord
slord@mathworks.com
comp.soft-sys.matlab (CSSM) FAQ: http://matlabwiki.mathworks.com/MATLAB_FAQ