Can you find the first and last names of all people who paid more than the rooms' base prices?
SELECT T1.firstname ,  T1.lastname FROM Reservations AS T1 JOIN Rooms AS T2 ON T1.Room   =   T2.RoomId WHERE T1.Rate - T2.basePrice  >  0
first and last names refer to firstname, lastname; people who paid more than the rooms' base prices refers to T1.Rate - T2.basePrice > 0;