f$.)$ The internal energy can be computed as follows:

$($:$E$:$)={\displaystyle \underset{i}{\overset{?}{}}}{p}_i{E}_i$

Where the sum is over all macrostates. Taking the energy of the complexed state as $E_{AB}=0$ and the

separated state as $E_{A+B}=lon,$ what is the expression of the internal energy for this two state system as a

function of $lon?$ Instead of writing out the numerical values for $W(E),$ write them as $W_{AB}$ and $W_{A+B}$ for the

complexed and separated states respectively.

Hint: the probability for the complexed state is: $p_{AB}=\frac{W_{AB}}{Q}$