A carpet cleaner charges$75 to clean the first 210 sq ft of carpet. There is an additional charge of25 per square foot for any footage that exceeds 210

sq ft and $1.40 per step for any carpeting on a staircase. Acustomer's cleaning bill was $253.95 This included the cleaning of a staircase with 13 steps. In addition to thestaircase, how many square feet of carpet did the customer havecleaned?

The customer had ? square feet of carpet cleaned.