Question 30444
Let's call X to the number of minutes Anastacia plans to use. If Anastacia takes the other plan, then the total fee she will pay is {{{15 + 0.30X}}}, because she will pay $15 plus $0.30 per minute.

Anastacia has chosen the $60 flat fee plan. That is because she expected this plan to be cheaper then the other one. So we have the inequality:
{{{60 < 15 + 0.30X}}}
So, solving for X,
{{{60-15<0.30X}}}
{{{45<0.30X}}}
{{{45/0.30<X}}}
{{{150<X}}}
We conclude that she is planning to use more then 150 minutes. If she planned to use less than that, then she should have chosen the non-flat plan