The amount of water remaining is 20 gallons when the time is 2 minutes.
A(n) = 12 when n = 4 minutes
Domain of the function A(n) is 0<= n <= 7.
Range of the function A(n) is 0<= A(n) <= 28
How to determine the range and domain of a function
From the graph
A(2)
The amount of water remaining is 20 gallons when the time is 2 minutes.
When the remaining water is 12 gallons the time is 4 minutes
A(n) = 12 when n = 4 minutes
Practical domain
Domain: In mathematics, the domain refers to the set of all possible input values (independent variable) for which a function or relation is defined.
n is defined at between 0<= n <= 7.
Practical range
Range: The range is the set of all possible output values of a function or relation, representing the dependent variable.
From the graph
range is 0<= A(n) <= 28