Functions Practice

​ Alicia is given $500 for her birthday and puts it in a savings account so that it will earn interest. The amount of money in the account is given by the function shown in the box, where A represents the amount, and t represents the time in years.

If D represents the domain, and R represents the range, which description identifies the domain and range of A(t).

• D: all real numbers;

  R: all real numbers

• D: ( 500, ∞); R: (0, ∞)

• D: R: all real numbers

• D: (0,∝); R: (500, ∝)

Jennie has a jar containing 800 mL of wax that she uses to make candles for her school project. She uses 50 mL of wax from the jar to make one candle. The function A(n)=800−50n represents the amount of wax left in the jar after making n candles.

What is the domain of the function A(n) in this context?

• all whole numbers

• all whole numbers less than or equal to 16

• all whole numbers less than or equal to 50

• all whole numbers less than or equal to 800

A small theater, with 250 seats, puts on plays. The profit the theater makes depends on the number of seats sold according to the function shown, P(n) = 6n − 120; where P is profit in dollars, and n is the number of seats sold. If the theater is unable to sell 20 or more seats, they will not open for that particular night.

What are the domain and range of this function, in the context of the situation?

• 0 ≤ n ≤ 120; 0 ≤ P ≤ 120

• 20 ≤ n ≤ 250; 0 ≤ P ≤ 1380

• 20 ≤ n ≤ 120; 6 ≤ P ≤ 200

• 0 ≤ n ≤ 250; 120 ≤ P ≤ 1380

Ellie records the outside temperature of -3ºF degrees at 6 a.m. The temperature increases by 2ºF every hour for the next 6 hours. If the temperature continues to increase at the same rate, what will the temperature be at 2:00 p.m.?

Tip: how many hours later? f(x) = 2(x) - 3

• -3ºF

• 3ºF

• 7ºF

• 13ºF

Evaluate the function for 𝙭 = 6

 𝘧(𝘹)=𝟦𝘹−𝟥

• 7

• -7

• 21

• 24

What function models the height of the periscope lens at time (t)? If the periscope reaches its maximum height after ascending for 22 seconds, what is the maximum height in feet? The periscope is 24 inches above the surface and ascends at 6 inches per second.

Tip: convert inches to feet to find maximum height

• f(t) = 6x + 24

  13 feet

• f(t) = 22x + 24

  12 feet

• f(t) = 24x + 6

  11 feet

• f(t) = 6x + 22

  10 feet

John has $200 in his bank account. He deposits $50 every month. If the amount in the bank is represented by the function f(x) = 50x + 200, where x is the number of months, what will be the amount in his bank account after 5 months?

• $250

• $350

• $450

• $550

Calculate the value of the function for 𝙭 = 8

 𝘧(𝘹)=𝟦𝘹+𝟦

• 36

• 32

• 28

• 24

What function models the depth of a submarine at time (t)? If the submarine reaches its maximum depth after descending for 30 seconds, what is the maximum depth in feet? The submarine is 36 inches below the surface and descends at 6 inches per second.

Tip: convert inches to feet to find maximum depth

• f(t) = 6x + 36

  18 feet

• f(t) = 30x + 36

  14 feet

• f(t) = 36x + 6

  13 feet

• f(t) = 6x + 30

  12 feet

A concert hall, with 300 seats, hosts music concerts. The revenue the hall makes depends on the number of seats sold according to the function shown, R(n) = 10n - 200; where R is revenue in dollars, and n is the number of seats sold. If the hall is unable to sell 20 or more seats, they will not open for that particular concert.

What are the domain and range of this function, in the context of the situation?

• 0 ≤ n ≤ 200; 0 ≤ R ≤ 200

• 20 ≤ n ≤ 300; 0 ≤ R ≤ 2800

• 20 ≤ n ≤ 200; 10 ≤ R ≤ 300

• 0 ≤ n ≤ 300; 200 ≤ R ≤ 2800