E21-31 Determining total mixed cost John Street Barber Shop pays $25 per month for water for the first 8,000 gallons and $3.50 per thousand gallons above 8,000 gallons. Calculate the total water cost when barber shop uses 7,000 gallons, 10,000 gallons, and 13,000 gallons. E21-31 Calculate the total water cost when the barber shop uses 7,000 gallons, 10,000 gallons, and 13,000 gallons. Solution: Total Water Cost 17.000 gal. 10,000 gal. 13,000 gal