Sounds stored in AU format have the extension .mp3

Ranjit wants to transfer pictures of a school play from his mobile to Manish's mobile. Suggest any two wireless mode of transmission which he can use for the same.

Pepsi company has its corporate office in one part of the city while the production unit is in another part of the same city. Which type of network is most suitable for communication between both the units?

Which type of network is used by the Indian Railways for providing their online services?