Question

An overseas telephone company charges $4 for the first minute of talking and then $0.25 for each additional minute. If a woman spent $13.75 talking on the phone, how many minutes did she talk for?

Answer 1

39 minutes

Explanation:

In this problem we can see that there is a constant/flat rate charge of $4 on every first minute

we can model the cost for calls as

`y= 4+0.25x------1`

where x is the number of extra minutes spent

given that y = $13.75

We can simply substitute our given values into the equation 1 above and solve for x

`13.75= 4+0.25x\\\\13.75-4= 0.25x\\\\9.75=0.25x`

Divide both sides by 0.25 to find x

`x= 9.75/0.25\\\\x=39`