how rare are thes checkmates

1: king and rook  only ,vs king

2: king, knight and bishop, vs king

3:  King and 2 bishops of different colours, vs king

I just managed to checkmate my opponent with king and rook. But how difficult and rare actually are these checkmates? and have they occurred in any of your games?

All of those are basic endings, but the #1 is the most common and easiest to execute. Personally I have never ended up with neither #2 nor #3, and I would say they are clearly rarer. 

Number 1 is easy to execute, use your king and rook to make a box and then shrink the box slowly useing your king, if possible keep your rook a knights move away from the opposing king.

Checkmating with a rook is fairly easy, and I have executed it many times. I have once checkmated with two bishops but never faced the challenge of winning with a knight and bishop.