WGU C957 Applied Algebra OA
Final Set Exam Real Questions
With Revised Correct Answers
Revised & Reviewed
1) For a school fundraiser, a local business will donate $1 for every
$10 donated by the community. What would the corresponding
coordinate be if the community raised $1,450?
(145, 14500)
(1450, 145)
(145, 1450)
(14,500, 1450)
- ANSWER (1450, 145)
Correct! The independent variable here is the amount raised in the
community, meaning you should list it first in the coordinate. The local
business' matching donation would then be $145, meaning the
coordinate should be (1450, 145).
2) Given the equation f(x)=3x+2
, what are the coordinates of the data point where x = 2?
(6, 2)
(2, 8)
(2, 0)
(8, 2)
,- ANSWER (2, 8)
Correct! When you substitute 2 for x in the equation, you get this:
(3×2)+2=8
. 2 is the x coordinate and 8 is the y coordinate.
3) Returning to the cell phone example from earlier in this lesson, how
many phone lines could you afford with a monthly cell phone budget of
$150? Express your answer in function notation.
Recall that the function B(x)=20x+50
modeled this situation where x is the number of phone lines and B is
the monthly bill.
B(4)=130
B(5)=140
B(5)=150
B(4)=150
- ANSWER B(5)=150
Correct! Five phone lines would cost exactly the $150 budgeted for cell
phones.
4) Now, say that for every new tablet, Carlo has to purchase an
additional computer rather than being able to replace one. Say also
that his company is a little bigger, with 30 computers. Let the function
C(t)
represent the number of computers the company has, where t is the
number of new tablets to be purchased.
Write an equation for C(t)
.
C(t)=t−30
C(t)=−t+30
C(t)=t+25
C(t)=t+30
,- ANSWER C(t)=−t+30
Correct! For each new tablet, Carlo will purchase one more computer,
adding to the existing 30 computers.
5) Remember, in her small firm, every 5 additional employees add
$10,000 to monthly revenue, which is presently estimated at $25,000.
Assuming the effect of adding employees is stable, write a function,
R(e)
, to model the company's monthly revenue in dollars, where e is the
number of new employees to be hired.
R(e)=2,000e+25,000
R(e)=2,000e+10,000
R(e)=25,000e+2,000
R(e)=10,000e+25,000
- ANSWER This equation implies each new employee adds $2,000
to the company's revenue, and the revenue is $25,000 if no new
employees are added.
For the correct function in the previous question, identify the
independent and dependent variables.
Independent : number of new employees
Dependent : monthly revenue
In a relatively predictable pattern, rooms in a house and the number of
people living there tend to correlate. For the moment, assume that all
houses have at least four basic rooms: a living room, a dining room, a
kitchen, and a bathroom. Beyond that, for every two residents of a
home, there will be one bedroom.
6) Larry is selling two different brands of computers: the Robin and the
Falcon. The Robin is an older model that sells for $250 each. The Falcon
, is a newer model that sells for $600 each. The function
F(x,y)=250x+600y models the total sales, in dollars, where x is the
number of Robin computers and y is the number of Falcon computers
sold.
Evaluate F(12,7) and interpret its meaning in the context.
$7,200
19
(3000, 4200)
$8,950
$7,200
Correct! F(12,7)
means to substitute x = 12 and y = 7 into the function. So,
F(12,7)=250(12)+600(7)=3000+4200=$7200
7) Write an equation in functional notation describing the number of
rooms in a house as a function of the number of people living within it;
then identify the independent and dependent variables.
Equation: R(p)=0.5p+4
Independent Variable: number of residents
Dependent Variable: number of rooms
Stay with Carlo for this question. Given the inverse function
T(c)=−2c+50
, what is T(15)
, and what does it mean?
T(15)=20; it implies that if the company keeps 15 computers, Carlo can
purchase 20 new tablets.
T(15)=15; it implies that Carlo can purchase 15 tablets.
T(15)=20; it implies that Carlo will have 20 computers left.
T(15)=15; Carlo will have 15 computers left.
