To check your Public IP visit :
4.b)Type ipconfig and hit enter.
4.c)The number shown against Ip Address is your Private ip.
You could assign Private ip on your own by :-
4.1)Double click on network connection icon in taskbar.
4.2)Click on Properties.
4.3)Click on internet protocol(tcp/ip).
4.4)Tick on “use this configuration”.
4.5)Enter your details.
4.6)Click on Ok.
Then their *Private ip* address could be checked at cmd via point 4). This *Private ip* is mostly *STATIC* .
But their *Public ip* will be same as they are connected to internet via same route ie same modem. This *Public ip* will be assigned by the ISP and may or may not be *Dynamic*.
2) Let us take another computer lab B with same configuration as lab A. Now let us suppose computer xyz. It will definately have a different *Public Ip* as compared to Lab A, but it may or may not have same *Private ip* as that of any computer in Lab A.
There is one more thing, two devices could never have same Private ip connected to a same network. But two devices connected to different network may or may not have same Private ip.
This mean two computers either from lab A or B, both could have same *Public ip* but can never have same *Private ip*.
Xyz computer From lab A:
Private ip : aaa.bbb.ccc.ddd [Generally STATIC]
Public Ip : xxx.yyy.zzz.www [Anything assigned by ISP, could be *DYNAMIC* or *STATIC* depending on your subscription]
Private Ip : eee.fff.ggg.hhh [this could be same as Private IP of XYZ in Lab A, Generally STATIC]
Public Ip : qqq.eee.www.ttt [This could never be same as that of lab A, anything assigned by ISP, could be *DYNAMIC* or *STATIC* depending on your subscription]