In which of the following processes is $\Delta S$ positive?

$A$ container is divided into two compartments by a removable partition as shown below:
In the first compartment,$n_{1}$ moles of ideal gas $He$ is present in a volume $V_{1}$. In the second compartment,$n_{2}$ moles of ideal gas $Ne$ is present in a volume $V_{2}$. The temperature and pressure in both the compartments are $T$ and $p$,respectively. Assuming $R$ is the gas constant,the total change in entropy upon removing the partition when the gases mix irreversibly is:

For an isolated system,$\Delta U = 0,$ what will be $\Delta S?$

When the value of entropy is greater,then the ability of work

$A$ system of $100 \ kg$ mass undergoes a process in which its specific entropy increases from $0.3 \ kJ \ kg^{-1} \ K^{-1}$ to $0.4 \ kJ \ kg^{-1} \ K^{-1}$. At the same time,the entropy of the surrounding decreases from $80 \ kJ \ K^{-1}$ to $75 \ kJ \ K^{-1}$. Find the $(\Delta S)_{universe}$ in $kJ \ K^{-1}$.

The total amount of energy in the universe is fixed,but