Table: gymnastics_2008_men_floor
Columns: position
gymnast
a_score
b_score
total

Question: what is the average b score when the gymnast is kōhei uchimura ( jpn )?
SQL: SELECT AVG("b_score") FROM gymnastics_2008_men_floor WHERE "gymnast" = 'kōhei uchimura ( jpn )'

Question: what is the b score when the a score is 6.9?
SQL: SELECT "b_score" FROM gymnastics_2008_men_floor WHERE "a_score" = 6.9

Question: what is the sum of the b score when the a score is 6.6 and the total is 15.6?
SQL: SELECT SUM("b_score") FROM gymnastics_2008_men_floor WHERE "a_score" = 6.6 AND "total" = 15.6