When your parents were younger, having a mobile phone was a big deal—if they were lucky enough to have one! But owning the phone was only half the challenge. Choosing the right phone plan was the other tricky part.

Question

Back then, neither texting nor talking was unlimited. In fact, carriers charged for both!

Here’s an example: VoiceStream offered a plan for $40 per month, plus an additional charge of 5 cents for every text sent.

If you send 100 text messages in a month, what would your total monthly cost be? Explain how you got your answer.

Answer 1

To calculate the total monthly cost for using the VoiceStream plan, we need to consider both the base monthly fee and the cost associated with sending text messages.

1. Base Monthly Fee: The monthly fee is $40.

2. Cost per Text Message: The plan charges 5 cents (or $0.05) for every text message sent.

3. Total Number of Text Messages: In this scenario, 100 text messages are sent.

Now, we calculate the total cost for the text messages:

• The cost for sending 100 text messages is: \[ 100 , \text{messages} \times 0.05 , \text{dollars/message} = 5 , \text{dollars} \]

4. Total Monthly Cost: We then add the base fee to the total text message cost: \[ 40 , \text{dollars (base fee)} + 5 , \text{dollars (text cost)} = 45 , \text{dollars} \]

So, the total monthly cost would be $45.