Python pip version paradox

Question

I downloaded Python 3.5.2 and installed it on 3 different computers. Now the weird part is that in each pc I got a different version of pip:

Computer 1 (win7-x64): pip --version -> 7.1.2
Computer 2 (win7-x64): pip --version -> 8.1.1
Computer 3 (win8.1-x64): pip --version -> 9.0.1

I guess my question is how is this even possible?

Answer 1

I believe you have previously installed Python on those PCs, and pip is not updated on installation of Python 3.5.2.