Table: mma_fight_results_28
Columns: res
record
opponent
method
event
round
time
location

Question: How many rounds had a time of 5:00 at UFC 155?
SQL: SELECT COUNT("round") FROM mma_fight_results_28 WHERE "time" = '5:00' AND "event" = 'ufc 155'

Question: Which event had a time of 2:34?
SQL: SELECT "event" FROM mma_fight_results_28 WHERE "time" = '2:34'

Question: Who was the opponent in the bout that led to a win in a time of 1:21?
SQL: SELECT "opponent" FROM mma_fight_results_28 WHERE "res" = 'win' AND "time" = '1:21'