[tex]\bf \begin{array}{ccllll}
hour&cost\\
\textendash\textendash\textendash\textendash\textendash\textendash&\textendash\textendash\textendash\textendash\textendash\textendash\\
1&42.50\\
3.5&x
\end{array}\implies \cfrac{1}{3.5}=\cfrac{42.50}{x}[/tex]
so... that'll give you the hourly charges
now, he also charges a $60 fixed amount
so, whatever you get in hourly charges, add 60 to that, and that's
the total bill
