We are given that the function for the cost of a call is:
[tex]C=2+1.5t[/tex]
Now, we determine the cost for speaking for 15 minutes by substituting the value of "t = 15":
[tex]C=2+1.5(15)[/tex]
Solving the operations:
[tex]C=24.5[/tex]
Since the cost is less than 25 this means that she can talk for 15 minutes and she would spend $24.5.
