a. 25 units of product 1 and 0 units of product 2.
b. All of resource 3 is being used (there is no slack for
constraint 3). A total of 25 units of resource 1 is being
used since there were 45 units available and there are 20
units of slack. A total of 75 units of product 2 being used
since there were 87 units available and there are 12 units
of slack.