How many country in the world?

It depends. Some countries don't recognize other countries as real countries.

Generally, there are about 194-196 countries recognized. But to be more exact, It is considered to be about 196 countries in the world although some countries, including the U. S, don't recognize Taiwan as a country although it "acts" like a country so that will bring it down to 195.

There are around 195 countries. Although it depends whether you consider some independent states or not to be countries.