Name: ________________________________
Date: __________________
Per: __________
ALGEBRA UNIT 1 MATRICES POSTTEST
Part I: Multiple Choice
Yes, you may write on this page! Write the letter of your answer on the blank line to the left of the question.
_______ (1) Use the following matrices to answer the question.
A copying company has 2 locations, one in Mapletown and the other in Oakdale. The owner keeps a
record of how many copies are made at each store using a matrix system. She records the number of
copies made by color and size of paper. The record for Monday morning is shown above. Which
matrix represents how many copies were made on Monday at both stores?
_______ (2) Use the matrices below to answer the question.
The amounts Kari and Sam earned for two days are shown in the matrices above. Which matrix
represents the amount saved each day?
_______ (3)
T =
[]
[]
5
4
-5
If T is multiplied by a scalar, the resulting matrix is
20
16
-20
What was the scalar?
A. 15
B. 4
C. -4
D. 20
_______ (4) Use the matrix below. What is 2A?
______ (5) What is X + Y given the matrices below?
[
[
[
[
3.8
X=
A.
]
]
]
]
7.2
2.1
3.8
8.9
15.1
5.6
10.5
Y=
B.
[14.5
[ ]
[] ][
25.6
5.1
7.9
3.5
6.7
C.
24
16.1
]
D.
[40.1]
_________ (6) Use the table below to answer this question.
Ashley
Julius
Quinton
Kiariun
Number of Candy Bars Sold
Plain Chocolate Chocolate with Peanuts Chocolate with Almonds
13
5
19
27
10
30
7
7
5
10
20
28
The table above shows the number of candy bars sold by 4 members of a club. Each candy bar costs $0.50.
Which matrix gives the dollar amount in sales for each type of bar for each club member?
__________ (7)
Rynada’s Flower Box sells tulip and gladiola bulbs to plant. The matrix above shows the
numbers of each type she ordered last year from 3 catalogs. This year Rynada will triple last
year’s order. Which matrix shows the number of bulbs she will order this year?
Part II: Open Response
Show your work in the spaces below. Be sure to write neatly and label your answers!
Item A
The table below represents the number of meals sold at a fast food restaurant for three different sizes of meals with
three different kinds of sandwiches. Use the table to answer the questions below.
Burger
Cheeseburger
Chicken
Kids
Regular Super Size
32
49
7
56
61
20
24
35
17
1. Organize the data into a matrix. You do not need to label the rows and columns.
2. What are the dimensions of your matrix?
3. Which size meal sold best overall?
4. All kids meals cost $2.00 each, regular meals cost $3.00, and super size meals cost $4.00. Create a matrix that
represents the sales in dollar amounts for each kind of meal with each kind of sandwich.
Item B
Johnathan organized the inventory in his shoe store according to brand and color. He then put the information into
the following matrix:
Jordans
Air Force Ones
Filas
1. On Monday morning, he sells 2 pairs of red Jordans and a new shipment of 5 pairs of Filas comes in. Write
a new matrix showing Johnathan’s updated inventory.
2. Johnathan decides that he wants to add a new color to his inventory. He orders the following: 10 pairs of
black Jordans, 7 pairs of black Air Force Ones, and 4 pairs of black Filas. Write a new matrix to represent
Johnathan’s inventory when the order comes in.
3. Johnathan decides to put all of his shoes on sale for $10 each. Create a matrix to represent the sales in
dollar amounts for each brand of shoe in each color. Use the inventory matrix from part 2.
4. Write an algebraic expression to represent the work you did in part 3. Be sure to define any variables used.