A water tank is 810 full. Then, 13 of the water it has is removed. Mark the alternative that expresses the capacity of the remaining tank.

The capacity of the remaining tank after 13 units of water have been removed can be calculated as: Remaining capacity = Initial capacity - Amount removed Remaining capacity = 810 - 13 Remaining capacity = 797 So, the correct alternative that expresses the capacity of the remaining tank is "797."