Table: melbourne_cup_2008
Columns: saddle_cloth
horse
trainer
jockey
weight_kg
barrier_b
placing

Question: Who rode mad rush?
SQL: SELECT "jockey" FROM melbourne_cup_2008 WHERE "horse" = 'mad rush'

Question: What place was the horse with a barrier of 20 and weighing less than 54 kg
SQL: SELECT "placing" FROM melbourne_cup_2008 WHERE "weight_kg" < 54 AND "barrier_b" = '20'

Question: What place was the viewed horse?
SQL: SELECT "placing" FROM melbourne_cup_2008 WHERE "horse" = 'viewed'