Finite Math
Test #1
Oct. 10, 2000
F Track
R. Hammack
Name: ________________________  
Score: _________

(1) Perform the indicated matrix operation, or explain why it cannot be done.

(a) [
5
1
][
1
4
]
=
 
2
3
2
0
 

(b) [
0
-1
3
]
+
[
0
1
2
] =  
4
7
1
-5
2
5
 

(2) Sketch the solutions of the following system of inequalities.

2x1
+
x2
8
x1
+
x2
5
x1
+
2x2
8
x1
0
   
x2
0

(3)

Maximize

subject to ...

 

P = 10x1 + x2

2x1
+
x2
8
x1
+
x2
5
x1
+
2x2
8
x1
0
   
x2
0

You may use any method. (However, notice that you sketched the feasible region in the previous problem. Feel free to use that information here.)


(4) Use Gauss-Jordan elimination to solve the following system of equations:

2x1
+
4x2
+
2x4
=
6
x1
+
2x2
+
x3
+
2x4
=
4

(5) Use the simplex method to solve the following problem.

A small publishing company is considering whether to publish 3 books. Let's call them book A, book B and book C. Two machines are needed to print the books, a printer and a binder. First a book is printed on the printer, then it is fed into the binder. Each copy of book A takes 6 minutes on the printer, then 4 minutes on the binder. Each copy of book B takes 4 minutes on the printer, then 2 minutes on the binder. Each copy of book C takes 2 minutes on the printer, then 1 minute on the binder. The printer is available for 1000 minutes per week, and the binder is available for 800 minutes per week. Each copy of book A will bring a profit of $2, each copy of book B will bring a profit of $1, and each copy of book C will bring a profit of $3. How many copies of each book shuld be made to realize a maximum profit?