The Charges for Renting a Moving Van Are $\$ 65$ For the First 40 Miles And

The charges for renting a moving van are $\$ 65$ for the first 40 miles and $\$ 5$ for each additional mile. Assume that a fraction of a mile is rounded up. (i) Determine the cost of driving the van 84 miles. (ii) Find a symbolic representation for a function $\mathrm { f }$ that computes the cost of driving the van $x$ miles, where $0 < x \leq 100$ . (Hint: express $\mathrm { f }$ as a piecewise-constant function.)

A) $\$ 685 ; f ( x ) = \left\{ \begin{array} { l l } 65 & \text { if } 0 < x \leq 40 \\ 65 + 5 ( x + 40 ) & \text { if } 40 < x \leq 100 \end{array} \right.$
B) $\$ 685 ; f ( x ) = \left\{ \begin{array} { l l } 65 & \text { if } 0 < x \leq 40 \\ 65 + 5 ( x - 40 ) & \text { if } 40 < x \leq 100 \end{array} \right.$
C) $\$ 285 ; f ( x ) = \left\{ \begin{array} { l l } 65 & \text { if } 0 < x \leq 40 \\ 65 + 5 ( x - 40 ) & \text { if } 40 < x \leq 100 \end{array} \right.$
D) $\$ 5680 ; f ( x ) = \left\{ \begin{array} { l l } 65 x & \text { if } 0 < x \leq 40 \\ 65 + 5 ( x - 40 ) & \text { if } 40 < x \leq 100 \end{array} \right.$