Simplify the following text for a Grade 12 native English-speaking person.
Original: Rhineland-Palatinate is divided into 24 districts , formerly grouped into the three administrative regions : Koblenz , Trier and Rheinhessen-Pfalz .
Simplified: Rhineland-Palatinate is divided into 24 districts , grouped into the three administrative regions : Koblenz , Trier and Rheinhessen-Pfalz .