Model and solve problems that involve piece-wise functions with and without technology.

A courier company charges delivery fees based on the distance travelled. For distances up to and including 10 km, the fee is a flat \$12. For distances greater than 10 km but up to and including 50 km, the fee is \$12 plus \$0.50 per kilometre travelled above 10 km. For distances greater than 50 km, the fee is \$32 plus \$0.30 per kilometre travelled above 50 km. (a) Write a piecewise function \(F(d)\) that represents the delivery fee in dollars for a distance of \(d\) kilometres. (1 mark) (b) Determine the delivery fee for a distance of 35 km. (1 mark) (c) Determine the delivery fee for a distance of 75 km. (1 mark)

A mobile phone plan charges a monthly fee according to the following piecewise function, where C(d) is the total cost in dollars and d is the data used in gigabytes (GB): C(d) = { 35 if 0 ≤ d ≤ 10; 35 + 8(d - 10) if 10 < d ≤ 25; 155 + 12(d - 25) if d > 25 } (a) Determine the monthly cost for a customer who uses 18 GB of data. (b) A customer's monthly bill is $191. Determine how many gigabytes of data this customer used.

A mobile phone plan charges customers based on their monthly data usage. The cost function \(C(d)\) (in dollars) for \(d\) gigabytes of data is defined by the piecewise function shown below. Which statement correctly describes the cost structure for this plan?