An average tub bath uses 8 gallons of water and an average shower uses 6 gallons. to provide baths for 60 people, how much more water will be needed if tubs are used instead of showers?

You need (8-6) 2 extra gallons to take a bath. With sixty people bathing, you'll need 60*2=120 extra gallons to meet the extra demand for water. Alternatively, you could note that 60 bathers*8 gallons per bath=480 gallons of water would be used for 60 baths and 60*6=360 needed for showers. The difference would be 480-360=120 gallons.