Four distinct times
Mina, Lio, Nori, and Ori each hold a ticket for a different time: 10:00, 10:15, 10:30, or 10:45. There are no delays; every clue concerns the printed times.
The departure notes
Ori leaves first. Mina leaves immediately after Nori, with no other departure between them. Lio is not the last to leave. Who holds the 10:30 ticket? “Immediately after” means neighboring departures, not simply later.
Place the fixed position first
Put the earliest traveler in the first box. In the remaining three boxes, Nori and Mina must form an adjacent block. Test its possible positions and see whether the place left for Lio violates the last clue.