Game Development

Normally how many days it take to develop or design a standard basic mobile game?

 

for a mobile game it would take 1 to 6 months to make if you are working on your own, if you have a team it would be considerably lower depending on project size

 

It highly depends on the target platform and the framework used to develop the mobile application.
C# developers would usually use Xamarin to write native applications for the Android, iOS and Windows Phone mobile platforms.
It is not supposed to take more than a few days to create a simple game (for example, Flappy Bird - as you asked about a basic game) as long as you have the graphics ready to use as game assets, possibly some background music and sound effects too.