Answer: 32 ounces.
Explanation:
We can think of this as a linear equation.
y = a*x + b
where y is the amount of water in the bottle, a is the rate at which loses water, x is the number of seconds and b is the initial amount of water.
We have two pairs:
2 seconds - 28 ounces left or (2, 28)
6 seconds - 20 ounces left or (6, 20)
Now we can write the value of a as:
a = (20 - 28)/( 6 - 2) = -8/4 = -2 ounces per second.
Then our function is:
y = -2x + b
and we know that when x = 2, y = 28, so we have:
28 = -2*2 + b = -4 + b
b = 28 + 4 = 32
the initial amount of water in the bottle is 32 ounces.