How many countries are Eurasian or transcontinental Europe and Asia?

Answer 1

For certain 2 -Russia and Turkey. However, a lot of the new states formed out of the former Soviet Union could also be considered part of both e.g. Ukraine and Belarus. Some people would also argue that some Middle Eastern states are part of Europe and/or Asia.

Unlike all other continents, the border between Asia and Europe is not clearly defined.

Answer 2

I believe that Russia and Turkey fit this description.