SELECT SUM(laps) FROM table_name_5 WHERE grid < 28 AND time = "retirement" AND bike = "ducati 1098 f08"
Berapa jumlah putaran dengan kisi kurang dari 28, waktu pensiun, dan sepeda Ducati 1098 F08?
CREATE TABLE table_name_5 (laps INTEGER, bike VARCHAR, grid VARCHAR, time VARCHAR)