Which is a type of passive transport

Well it depends on the permeability of the cells membrane.
There are 4 types: simple diffusion, facilitated diffusion, filtration, osmosis

The two types of passive transport are diffusion and osmosis. Diffusion is the movement of molecules across a membrane from an area of high concentration to an area of low concentration, occurring with or without the help of membrane proteins. Osmosis is the diffusion of water molecules.

An egg, or a sack of flour