Change in entropy equation when pressure changes

[Melissa Kulon 2D]

I was reviewing my notes from different chemistry reviews and one TA had said that when our pressure changes, our equation for entropy change is ΔS=nRln(P2/P1) but another one had written ΔS=nRln(P1/P2). Just wanted to clarify which equation is correct. Thanks!

[Lisa Leung 2H]

It should be the second one because the original equation is ΔS=nRln(V2/V1) and P and V have inverse relationships(PV=nRT) so it should be ΔS=nRln(P1/P2).