What is the surface at the tournament of Vaihingen?
CREATE TABLE table_name_24 (surface VARCHAR, tournament VARCHAR)
SELECT surface FROM table_name_24 WHERE tournament = "vaihingen"
### Context: CREATE TABLE table_name_24 (surface VARCHAR, tournament VARCHAR) ### Question: What is the surface at the tournament of Vaihingen? ### Answer: SELECT surface FROM table_name_24 WHERE tournament = "vaihingen"