Percentages are ratios of an amount compared to 100. The percent change of an old to new value is equal to 100% x \({ new - old \over old }\).
The total water usage for a city is 40,000 gallons each day. Of that total, 23% is for personal use and 55% is for industrial use. How many more gallons of water each day is consumed for industrial use over personal use?
| 12,800 | |
| 600 | |
| 3,800 | |
| 16,500 |