It will not be filled until 2 pm because the pool is filling up at a rate of 600gal every 15 min.
600x20=12,000 gal at 12 pm
600x28=16,800 gal at 2pm
How I got the time was there are 60 minutes in an hour divide that by 15 equals 4. And there is 5 hours between 8-12 so 5x4=20
