186k views
1 vote
A telephone carrier charges customer 0.99 cents for the first 10 minutes and then 0.06 for each minute beyond 10 min. If Mary uses this carrier, how long can she talk for $6.00

User Raju Ram
by
7.7k points

1 Answer

2 votes

We have the following function for this problem:


\begin{cases}f(t)=0.99,t\leq10 \\ f(t)=0.06(t-10)+0.99,t>10\end{cases}

Where 't' represents the time in minutes, and our 'f(t)' returns the cost.

For f(t) = 6, we want to know the value for 't'. Clearly, it is not in the first interval, so let's check for t >10.


6=0.06(t-10)+0.99

Solving for 't':


\begin{gathered} 5.01=0.06(t-10)_{} \\ 83.5=t-10 \\ 93.5=t \end{gathered}

Mary can talk for 93 minutes.

User Stephanie Schaye
by
7.9k points

No related questions found

Welcome to QAmmunity.org, where you can ask questions and receive answers from other members of our community.

9.4m questions

12.2m answers

Categories