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Applications of Mathematics 12
Matrices
Problem Solving with Matrices
Problem 1:
The table below shows the standings for three local hockey teams:
Team
Wins
Ties
Losses
Blazers
7
2
4
Hawks
5
1
7
Tigers
8
0
5
There are two scoring methods:
Method 1
Win = 2 points
Tie = 1 point
Loss = 0 points
Method 2
Win = 3 points
Tie = 2 point
Loss = 1 points
Calculate the points for each team using each method. Show the calculations.
Method 1:
Blazers
Hawks
Tigers
Method 2:
Blazers
Hawks
Tigers
page 1
Applications of Mathematics 12
Matrices
NOW : Let’s solve the same problem using Matrices :
Matrix A =
Matrix B =
Matrix C =
Dimensions of A =
Dimensions of B =
Dimensions of C =
Calculate A  B
and explain the meaning of your answers
Calculate A x C
page 2
Applications of Mathematics 12
Matrices
Problem 2:
A company makes wooden toys. The toys must be cut and assembled. The table below
shows the labour hours for each toy.
Cutting hours Assembling hours
Train
0.5
0.6
Boat
0.4
0.4
Plane
0.2
0.5
The company has an order for 500 trains, 300 boats, and 550 planes. Use matrix
multiplication to determine the total cutting time and the total assembling time needed to
make the order.
If it costs $12.00 an hour for cutting and $ 9.00 an hour for assembling, what will be the
total cost for this order?
page 3
Applications of Mathematics 12
Matrices
Problem 3:
SoftSell Corp. sells software at three locations. The sales at each location for different
categories of software are given for a 1 week period.
Entertainment
Business
Educational
Location 1
200
50
120
Location 2
300
100
50
Location 3
250
150
200
Entertainment software costs $60 each, business software costs $80 each, and educational
software costs $75 each. Use matrix multiplication to find the total revenue for each
location.
page 4
Applications of Mathematics 12
Matrices
Problem 4:
The following table shows prices at three grocery stores:
Item
Saveway
IMA
Supershop
Milk 1L
$1.13
$1.19
$1.21
Bread 1 loaf
$1.09
$1.12
$0.99
Eggs 1 dozen
$1.22
$1.35
$1.33
Soup 1 can
$0.55
$0.45
$0.60
Three customers want to place orders.
Person 1 wants to buy 5L of milk, 3 loaves of bread, 2 dozen eggs and 6 cans of soup.
Person 2 wants to buy 2L of milk, 5 loaves of bread, 3 dozen eggs, and 4 cans of soup
Person 3 wants to buy 3L of milk, 5 loaves of bread, 4 dozen eggs and 5 cans of soup
Use matrix multiplication to determine the total costs for each of these three orders for
each store.
 Assignment : You may use your calculator for the matrix operations. Please write down
your steps clearly. CHECK YOUR ANSWERS !!!!!
Textbook page 55 # 1, 6,7
page 64 #1 to 7
page 5