Ok, this definition of f is just a bunch of points (4 to be exact).
so if point (a,b) is part of f, then f(a)=b
f(1) is about point (1,0), so f(1)=0.
g(1) = 1 (due to point (1,1))
g(2/3) = 0
f(2) = 3/4
g(-2) = 3
f(π) = -2
just a lookup once you see what is happening
Find out how much you filled.
2.92 + 3.14 = 6.06 L
Find the remaining.
8.23 L - 6.06 L = 2.17 L
You need 2.17 L more to fill the water jug
The answer to this question is E.
I divided the two fractions & drew a model.

So we know that the bird seed will last 2.5 days.
Knowing this, we can go with:
B. Rectangle model divided into six equal sections, five sections are labeled five-sixths and two sections are labeled one-third, equaling two and one-half days.
Let me know if you find any problems with my answer.