If the pressure of a gas in a closed container is reduced,the mean free path of the molecules will ......

If the diameter of a gas molecule is very small,what will be the mean free path?

If the mean free path of atoms is doubled,then the pressure of the gas will become:

At a temperature of $314 \,K$ and a pressure of $100 \,kPa$, the speed of sound in a gas is $1380 \,ms^{-1}$. The radius of each gas molecule is $0.5 \,Å$. The frequency of sound at which the wavelength of the sound wave in the gas becomes equal to the mean free path of the gas molecules is (Boltzmann constant $k = 1.38 \times 10^{-23} \,JK^{-1}$):

An ideal gas in a closed container is slowly heated. As its temperature increases,which of the following statements are true?
$(A)$ The mean free path of the molecules decreases.
$(B)$ The mean collision time between the molecules decreases.
$(C)$ The mean free path remains unchanged.
$(D)$ The mean collision time remains unchanged.

What is free path? And what is mean free path?