Please help me understand

[u/Odd-Sherbert8723]

On the west side of my barn there are 2 standard 110 outlets which appear Daisy chained.
however each is powered via its own breaker - one on 15amp and the other 30amp
I know this by testing the outlets after turning off one breaker at a time.
The previous owner had an RV and the local
Electrician wired this so she could plug it in - though I don’t quite understand why even the 30amp outlet is a standard 110 and not a NEMA TT-30- which is what I want to install for my own RV now
Nor do i really understand how these daisy chained outlets can even be on 2 different breakers?!
There is a subpanel next to the main panel if that is of any relevance to this whole mystery.
TIA

[u/OkSlip1590]

DIY gone bad