Table: race_results_5
Columns: result
date
race
venue
group
distance
weight_kg
time
jockey
winner_2nd

Question: How many entries are there for weight when the winner is 1st - defier and venue is randwick?
SQL: SELECT COUNT("weight_kg") FROM race_results_5 WHERE "winner_2nd" = '1st - Defier' AND "venue" = 'Randwick'

Question: Who was the jockey at Rosehill and the weight was 57.5 kg?
SQL: SELECT "jockey" FROM race_results_5 WHERE "venue" = 'Rosehill' AND "weight_kg" = '57.5'

Question: When the time is 1:36.30 what shows as winner?
SQL: SELECT "winner_2nd" FROM race_results_5 WHERE "time" = '1:36.30'