One cell phone plan allows 200 text messages per month for $20 after which text messages cost $0.04 each. Another cell plan allows 400 text essages per month for $30 each. What would be the minimum text messages that would justify the more expensive plan

Answer 1

I assume plan B is a flat $30/month. If so, the costs are equal for x minutes if

20+0.04(x-200) = 30

And the question is poorly worded.