Cody’s brother lives on the top floor.
Marcus, Roger, and Cody took the elevator to visit Cody’s brother’s room. Then they ran down 5 flights of stairs. They realized they’d overshot their destination, so they took an elevator up 1 floor to get to Roger’s brother’s room.
From Roger’s brother’s room the three boys went down 6 flights of stairs to visit Marcus’s sister. From her room they took the elevator up 4 floors, where they met Brittany and her brother getting on at his floor.
Erin and her sister walked up 2 flights from the lobby to get to Erin’s sister’s room.
On what floor does each of the college students live?