Math section 8 part 2

Question

Although not so common now, consider a phone plan that does not have unlimited texting. Your base plan costs you $30 a month and each text sent or received is only 12 cents. Write an equation to describe the total monthly cost of your bill with x text messages and y cost in dollars. Do not use spaces for your answer.

 

In one month 217,000 messages were sent between two brothers in Philadelphia. What was their approximate bill? (This is a true story!)

Answer 1

Hi John Marc,

I wanted to offer a little help on this problem.

This is a linear equation, as we know that each month, you pay a flat $30 plus a rate of $0.12 / minute. So, if we wanted to see how much these brothers had to pay for their texing and phone plan, we could use the following equation:

y = 0.12 x + 30

Now, we are given the exact number of text received and sent. So each brother pays for both sending and receiving a text, so we know they would each pay the following:

y = 0.12*(217,000) + 30

y = $26,070

In other words, these brothers saved a lot of money when they switched to unlimited texting plans!

Please let me know if you have any questions!

Kali