So start with the top one and end w the bottom
8 pigs x 4 legs each = 32. so you need 2 ducks to give you 10 animals total. So 32 + 2 ducks with 2 legs = 36.
There are 8 pigs and 2 ducks.
Answer : I need a graph or something
If

then

Differentiating with respec to
gives


So
is indeed conservative, and
