Hi, all,

I am a new learner in AMPL and I can't figure out how to solve the

problem below by using AMPL. Can you be kind enough to share me the

language used in AMPL step by step? Thanks in advance for your help.

Problem: Sunco oil has three different processes that can be used to

manufacture various types of gasoline. Each process involves blending

oils in the company's catalytic cracker. Running process 1 for an hour

costs $5 and requires 2 barrels of crude oil 1 and 3 barrels of crude

oil 2. The output from running process 1 for an hour is 2 barrels of

gas 1 and 1 barrel of gas 2. Running process 2 for an hour costs $4

and requires 1 barrel of crude 1 and 3 barrels of crude 2. The output

from process 2 for an hour is 3 barrels of gas 2. Running process 3

for an hour costs $1 and requires 2 barrels of crude 2 and 3 barrels

of gas 2. The output from running process 3 for an hour is 2 barrels

of gas 3. Each week, 200 barrels of crude 1, at $2/ barrel, and 300

barrels of crude 2 at $3/barrel, may be purchased. All gas produced

can be sold at the following per-barrel prices: gas 1, $9; gas 2, $10;

gas 3, $24. Formulate an LP whose solution will maximize revenues less

costs. Assume that only 100 hours of time on the catalytic cracker are

available each week.

My Solution:

Let X_i = no. of hours process i is run per week (where i =1,2,3)

Let O_i = no. of barrels of oil i that is purchased per week (i =1,2)

Let G_2 = no. of barrels of gas 2 sold per week

maximize cost= 9(2*X_1)+10(G_2)+24(X_3)-5(X_1)-4(X_2)--2(O_1)-3(O_2)

=13X_1-4X_2+47X_3+10G_2--2(O_1)-3(O_2)

constraints:

2X_1+X_2-O_1=0

3X_1+3X_2-O_2=0

X_1+3X_3-G_2=0

X_i, O_i ,G_2>=0

O_1<=200

O_2<=300

sum{X_i}<=100

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