Table: camino_stages
Columns: stage
start
arrival
duration
difficulty

Question: Which stage number did son bou arrive at?
SQL: SELECT COUNT("stage") FROM camino_stages WHERE "arrival" = 'son bou'

Question: How long does the one that stars with son bou of middle difficulty, and on a stage number larger than 13 last?
SQL: SELECT "duration" FROM camino_stages WHERE "stage" > 13 AND "difficulty" = 'middle' AND "start" = 'son bou'

Question: What is the lowest stage number that starts with els alocs and has a middle difficulty?
SQL: SELECT MIN("stage") FROM camino_stages WHERE "difficulty" = 'middle' AND "start" = 'els alocs'