What was the challenge for episode 28?
CREATE TABLE table_24798489_2 (challenge VARCHAR, episode_number VARCHAR)
SELECT challenge FROM table_24798489_2 WHERE episode_number = 28
### Context: CREATE TABLE table_24798489_2 (challenge VARCHAR, episode_number VARCHAR) ### Question: What was the challenge for episode 28? ### Answer: SELECT challenge FROM table_24798489_2 WHERE episode_number = 28