HSA 2006 Algebra/Data Analysis Item 21

Art's swimming pool contains 20,000 gallons of water. He drains the pool at a rate of 5 gallons per minute. Which of these equations represents the number of gallons of water (g) remaining in the pool after m minutes?

1. g = 20,000 - 5m
2. g = 20,000 + 5m
3. g =
4. g =