Question

we can get the smell of perfume sitting several metres away

Answer 1

This is due to diffusion. the particles of perfume diffuse in the air and can reach us sitting far away. the same thing happens with the smell of incense stick. 

Answer 2

We can get the smell of perfume several metres away due the diffusion of perfume vapours into air. When liquid perfume is applied by a person. It quickly changes into vapour. The perfume vapours move very rapidly in all directions mix with air particles by diffusion and spread and so we can get the smell of perfume several metres away



Hope it helps u