Write the Word or Phrase That Best Completes Each Statement

Short Answer

Write the word or phrase that best completes each statement or answers the question.
-One Internet service provider has the following rate schedule for high-speed Internet service: $$\begin{array} { l l } \text { Monthly service charge } & \$ 18.00 \\& \\1 \text { st } 50 \text { hours of use } & \text { free } \\\text { Next } 50 \text { hours of use } & \$ 0.25 / \text { hour } \\\text { Over } 100 \text { hours of use } & \$ 1.00 / \text { hour }\end{array}$$ What is the charge for 50 hours of high-speed Internet use in one month?
What is the charge for 75 hours of high-speed Internet use in one month?
What is the charge for 135 hours of high-speed Internet use in one month?