Question

For his phone service, Ahmad pays a monthly fee of $23, and he pays an additional $0.05 per minute of use. The least he has been charged in a month is$96.75.What are the possible numbers of minutes he has used his phone in a month?Use m for the number of minutes, and solve your inequality for m.

Answer 1

First, we must find the total amount C charged in a month for m minutes that Ahmad spend in the phone.

We know that the monthly fee is $23 and there is an additional charge of $0.05 for every minute of use. Therefore, we have:

`C=0.05m+23`

Since the least he has been charged in a month is $96.75, we have:

`\begin{gathered} C\ge96.75 \\ 0.05m+23\ge96.75 \\ 0.05m\ge96.75-23 \\ 0.05m\ge73.75 \\ m\ge(73.75)/(0.05) \\ m\ge1475\text{ minutes} \end{gathered}`