Question

For her phone service, Kira pays a monthly fee of $13, and she pays an additional $0.05 per minute of use. The least she has been charged in a month is$77.35.What are the possible numbers of minutes she has used her phone in a month?Use m for the number of minutes, and solve your inequality for m.

Answer 1

monthly fees = $13

Additional fees = $0.05 per minute

The least she has been charged in a month = $77.35

number of minutes = m

Therefore,

`\begin{gathered} 13+0.05m\ge77.35 \\ 0.05m\ge77.35-13 \\ 0.05m\ge64.35 \\ m\ge(64.35)/(0.05) \\ m\ge1287\text{ minutes} \end{gathered}`