Table: race_results_30
Columns: rd
event
circuit
city_state
date
championship
challenge
production

Question: What circuit was the Clipsal 500 on?
SQL: SELECT "circuit" FROM race_results_30 WHERE "event" = 'Clipsal 500'

Question: Who made the challenge on the Albert Park Grand Prix Circuit?
SQL: SELECT "challenge" FROM race_results_30 WHERE "circuit" = 'Albert Park Grand Prix Circuit'

Question: In what round was the circuit Eastern Creek Raceway?
SQL: SELECT "rd" FROM race_results_30 WHERE "circuit" = 'Eastern Creek Raceway'

Question: Who made the challenge in the Australian Grand Prix?
SQL: SELECT "challenge" FROM race_results_30 WHERE "event" = 'Australian Grand Prix'