Table: swimming_2007_women_im
Columns: place
lane
name
nationality
50m_split
100m_split
150m_split
time

Question: Which nationality has a split in the 50m of 29.51?
SQL: SELECT "nationality" FROM swimming_2007_women_im WHERE "50m_split" = 29.51

Question: Which average 50m split had a 150m split of 1:40.00, with a placing of less than 2?
SQL: SELECT AVG("50m_split") FROM swimming_2007_women_im WHERE "150m_split" = '1:40.00' AND "place" < 2