Real-Life Functions: Word Problems & Variables for Grade 8

A car rental company charges a flat fee of $50 plus $0.20 per mile driven. If you drive 'm' miles, how can you express the total cost 'C' as a function of 'm'?

• C(m) = 50 - 0.20m

• C(m) = 50 + 0.20m

• C(m) = 50 + 0.50m

• C(m) = 0.20 + m

A bakery sells cupcakes for $3 each. If 'n' represents the number of cupcakes sold, write a function 'C(n)' that represents the total revenue from selling 'n' cupcakes. What is the independent variable?

• C(n)

• n

• total revenue

• $3

A gym charges a monthly fee of $30 plus $5 for each class attended. If 'c' is the number of classes attended, express the total cost 'T' as a function of 'c'. What does 'c' represent?

• T(c) = 30 + 5c

• T(c) = 30 - 5c

• T(c) = 5c

• T(c) = 30 + c

A phone plan costs $25 per month plus $0.10 for each text message sent. If 't' is the number of text messages sent, write the function 'P(t)' for the total monthly cost. Identify the independent variable.

• P(t) = 25 + 0.05t; independent variable is cost.

• P(t) = 0.10 + 25t; independent variable is t.

• P(t) = 25t + 0.10; independent variable is P.

• P(t) = 25 + 0.10t; independent variable is t.

A farmer sells apples for $2 per pound. If 'p' represents the number of pounds sold, express the total income 'I' as a function of 'p'. What is the independent variable in this scenario?

• I(p) = 2p; independent variable is 'p'.

• I(p) = 2 + p; independent variable is 'p' and 'I'.

• I(p) = 2p^2; independent variable is '2'.

• I(p) = p + 2; independent variable is 'I'.

A movie theater charges $12 per ticket. If 'x' is the number of tickets sold, write a function 'R(x)' for the total revenue. What does 'x' represent?

• R(x) = 12 / x; x represents the price per ticket.

• R(x) = 12 * x; x represents the number of tickets sold.

• R(x) = 12 - x; x represents the number of seats available.

• R(x) = 12 + x; x represents the total cost.

A subscription service charges $15 per month. If 'm' is the number of months subscribed, express the total cost 'C(m)' as a function of 'm'. Identify the independent variable.

• C(m) = 15m; independent variable is m.

• C(m) = m/15; independent variable is C.

• C(m) = 15 + m; independent variable is C.

• C(m) = 15m^2; independent variable is m.

A delivery service charges a base fee of $5 plus $1 for each mile driven. If 'd' is the distance in miles, write the function 'F(d)' for the total fee. What does 'd' represent?

• d represents the delivery fee.

• d represents the number of packages delivered.

• d represents the distance in miles.

• d represents the time taken for delivery.

A school sells tickets for a fundraiser at $10 each. If 's' is the number of tickets sold, express the total amount raised 'A(s)' as a function of 's'. Identify the independent variable.

• A(s) = 5 * s; independent variable is 'A'.

• A(s) = s + 10; independent variable is 's'.

• A(s) = 10 + s; independent variable is 't'.

• A(s) = 10 * s; independent variable is 's'.

A concert venue charges $50 for a ticket and an additional $5 for parking. If 't' is the number of tickets purchased, write the function 'C(t)' for the total cost. What does 't' represent?

• C(t) = 55t; 't' represents the number of parking spots.

• C(t) = 50t + 5; 't' represents the number of tickets purchased.

• C(t) = 50t + 10; 't' represents the number of cars parked.

• C(t) = 50 + 5t; 't' represents the total cost.