Function Rule Word Problems

A taxicab charges $4.25 for a ride and $1.50 per mile. Write a rule for describing the total rate r as a function of the total miles m. What is the taxi rate for 12 miles?

• 22.25

• r = 4.25m + 1.50

• 52.50

• r = 1.50m + 4.25

A water tank already contains 55 gallons of water when Baxter begins to fill it. Water flows into the tank at a rate of 8 gallons per minute. Select the linear function rule to model this situation. Then find the volume of water in the tank 25 minutes after Baxter begins filling the tank.

• 255

• f(x) = 8x + 55

• 1383

• f(x) = 55x + 8

Bob has $150 in his savings account and saves $40 per month.

• f(x) = 150 + 40

• f(x) = 40x + 150

• f(x) = 150x + 40

Which of the following situations could be descried by the equation f(x) = - 25x + 120

• There are 120 people in the football stadium, and 25 more are entering each hour.

• A plumber charges $25 for a house call and $120 per hour.

• A teacher has 120 students. Her third period has 25 students

• There are 120 gallons of water in a tank. It releases water at a rate of 25 gallons per minute

Identify the function rule that best represents the following statement:
A bottle rocket is being launched from the roof of an 80 meter tall building. If the rocket travels straight up at a rate of 22 m/s, what is the total height of the rocket as a function of time?

• H = 108x

• H = 80 - 22x

• H = 80 + 22x

• H = 80x + 22

• -12

• -43

• 29

• -29

A plumber charges a service fee of $40 plus $25 per hour for labor.
Write a function rule for the total cost of hiring the plumber for a job that takes x hours.
How much would it cost to hire the plumber for a job that takes 4 hours?

• y = 40 + 25x
  $140

• y = 40x + 25
  $185

• y = 40 + 25x 
  $185

• y = 40x + 25 
  $140

The school cafeteria has 285 cartons of milk in stock. Each day, a total of 60 cartons are sold. Which function rule best represents this situation?

• y = 285x + 60 

• y = 285x - 60

• y = 285 - 60x

• y = 285 + 60x

The temperature (T) increases by 5 degrees Fahrenheit every hour. Write a function rule to represent the temperature after 'h' hours if the initial temperature is 70 degrees Fahrenheit.

• T=70 * 5h

• T=70 + 5h

• T=70 - 5h

• T=70 + 5h

The cost of renting a bicycle is $10 per hour. Write a function rule to represent the total cost (C) of renting the bicycle for 'h' hours.

• C = 5h

• C = 20h

• C = 10h

• C = 10/h