Question

A vacation cabin has a water storage tank. In the first month (30 days) of the vacation season, the amount of water in the tank changed by an average of -36 gallons per day. At the end of the month, the tank contained 1,340 gallons of water. How much water was in the tank originally?

Answer 1

36 times 30 equals 1,080.
add 1,080 to 1,340 and your answer is 2,420 gallons