Answer:
1595790 gallons
Explanation:
Given that;
3.8 L = 1 US gallon
303,200.0 liters = 303,200.0 * 1/ 3.8 = 79789.5 gallons
If a wave is made every 90 seconds which is 1.5 mins
Then;
Number of waves made in 30 minutes = 30/1.5 = 20 waves
if each uses 79789.5 gallons, then 20 waves will use 20 * 79789.5 gallons = 1595790 gallons