The temperature of the system decreases in the process of

$A$ sample of an ideal gas is contained in a cylinder. The volume of the gas is suddenly decreased. $A$ student makes the following statements to explain the change in pressure of the gas:
$I.$ The average kinetic energy of the gas atoms increases.
$II.$ The atoms of the gas hit the walls of the cylinder more frequently.
$III.$ Temperature of the gas remains unchanged.
Which of these statements is true?

An ideal gas at $27 \, ^\circ C$ is compressed adiabatically such that its volume becomes $8/27$ of its original volume. If $\gamma = 5/3$ for the gas,the increase in temperature of the gas is ..... $K$.

An ideal gas at $27^{\circ}\text{C}$ is compressed adiabatically to $(8/27)$ of its original volume. If $\gamma = 5/3$, then the rise in temperature of a gas is (in $\text{ K}$)

$A$ monoatomic gas $(\gamma = 5/3)$ is suddenly compressed to $1/8$ of its original volume adiabatically. The pressure of the gas will change to:

$A$ monatomic gas at a pressure of $100 \text{ kPa}$ expands adiabatically such that its final volume becomes $8$ times its initial volume. If the work done during the process is $180 \text{ J}$, then the initial volume of the gas is (in $\text{ cm}^3$)