Solve this, its tricky!?

Selena has 31 days to complete her quilt for the county fair. The blue squares in the quilt can be sewn at a rate of 4 squares per day, and the white squares at a rate of 7 squares per day. The quilt can have up to 96 squares total. The blue fabric b costs about $0.80 per square and the white fabric w costs about $1.20 per square. Selena wants to keep costs at a minimum. Write an inequality that expresses the total number of squares to be sewn.