1. As the leader of an oil-exploration drilling venture, you must determine the leastcost selection of 5 out of 10 possible sites. Label the sites S 1


,S 2

,…,S 10

, and the exploration costs associated with each as C 1

,C 2

,…,C 10

. Regional development restrictions are such that: (a) Exploring sites S 1

and S 7

will prevent you from exploring site S 8

; (b) Evaluating site S 3

or S 4

prevents you from exploring site S 5

; and (c) Of the group S 5

,S 6

,S 7

,S 8

, only two sites may be explored. Formulate this problem as an integer programming problem.

1 answer

Let's define binary decision variables for each site, such that:

X1 = 1 if site S1 is selected, 0 otherwise
X2 = 1 if site S2 is selected, 0 otherwise
...
X10 = 1 if site S10 is selected, 0 otherwise

The objective is to minimize the total exploration cost, which can be formulated as:

Minimize: C1*X1 + C2*X2 + ... + C10*X10

Subject to the following constraints:

1. Exploring sites S1 and S7 prevents exploring site S8:
X1 + X7 <= 1

2. Evaluating site S3 or S4 prevents exploring site S5:
X3 + X4 <= 1

3. Only two sites from the group S5, S6, S7, S8 can be explored:
X5 + X6 + X7 + X8 <= 2

4. The number of selected sites must be 5:
X1 + X2 + ... + X10 = 5

Also, it is important to note that X1, X2, ..., X10 should be binary variables.