Real World Domain and Range

A holiday church's meal costs $12.50 a person plus a delivery fee of $30. The equation is: f(x)=30+12.5x, where x is the number of hungry people. If there are 15 people in the church, what is the domain?

• 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15

• 0, 42.50, 55, 67.50, 80, 92.50, 105, 117.50, ....

• None of the above.

Leslie's car travels about 25 miles per gallon of gas. Her car needs 14 gallons of gas to be full. What is a reasonable domain?

A student is taking a test that has 10 questions on it. The student's score is a function of how many questions he misses: f(x)=100-10x, where x is the number of questions incorrect. What is the domain?

• 0, 1, 2, 3, 4, 5, 6, 7, 8, 10, 11, 12, 13, 14, 15, 16

• 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10

• 0 < x < 10

• x < 10

A student is taking a test that has 10 questions on it. The student's score is a function of how many questions he misses: f(x)=100-10x, where x is the number of questions incorrect. What is the range?

• 10, 20, 30, 40, 50, 60, 70, 80, 90, 100

• 0, 10, 20, 30, 40, 50, 60, 70, 80, 90, 100

• 0 < y < 100

• y < 100

The total cost in dollars, c, to purchase video games online can be found using the function c = 16.95x + 4.75, where x is the number of video games purchased.  If at least 4 games but no more than 7 games are purchased online, what is the range of the function for this situation?

• {4, 5, 6, 7}
• 4 ≤ x ≤ 7
• 72.55 ≤ c ≤ 123.50
• {72.55, 89.50, 106.45, 123.40}

Mario has and iTunes gift card worth $20.00. He uses the formula    y=0.99x to determine y, the total cost for x number of songs. What is the domain for the situation?

• All integers between 0 and 20
• All real numbers between 0 and 19.80
• All integers greater than 0
• All integers between 0 and 250

A pizza shop sells pizza for $7.50 each plus $1.25 per topping. The total price of the pizzas can be determined by the function P(t) = 7.5 + 1.25t, where te is the number of toppings orders and P(t) is the total price of the pizza. The shop has a delivery policy that all orders must have a minimum of 2 toppings and maximum of 8 toppings for a delivery. Which inequality represents the range of the situation?

• {10, 11.25, 12.50, 13.75, 15, 16.25, 17.50}

• {2, 3, 4, 5, 6, 7, 8}

• 10 ≤ P(t) ≤ 17.50

• 0 ≤ P(t) ≤ 17.50

Speedy Boat Rental charges a $15 deposit fee plus $2 for each hour of use to rent a paddle boat. The equation: C=2h+15. If Frank has $33 to spend, what is the domain of the situation?

• 0 < x < 9

• 0, 1, 2, 3, 4, 5, 6, 7, 8, 9

• 15, 17, 19, 21, 23, 25, 27, 29, 31, 33

• 0 < y < 33

Speedy Boat Rental charges a $15 deposit fee plus $2 for each hour of use to rent a paddle boat. The equation: C=2h+15. If Frank has $33 to spend, what is the range of the situation?

• 0 < y< 33

• 0<y<33

• 15, 17, 19, 21, 23, 25, 27, 29, 31, 33

• 1, 2, 3, 4, 5, 6, 7, 8, 9, 10

The daily cost of hiring a plumber, y, to work x hours on a repair project can be modeled using a linear function. The plumber charges a fixed cost of $80 plus an additional cost of $45 per hour. The plumber works a maximum of 8 hours per day.

For one day of work, what is the range of the function for this situation?