Table: soo_line_locomotives_3
Columns: class
wheel_arrangement
fleet_number_s
manufacturer
year_made
quantity_made
quantity_preserved

Question: What is the quantity preserved when 4 were made of class F-21?
SQL: SELECT "quantity_preserved" FROM soo_line_locomotives_3 WHERE "quantity_made" = '4' AND "class" = 'f-21'

Question: What fleet number had 3 made?
SQL: SELECT "fleet_number_s" FROM soo_line_locomotives_3 WHERE "quantity_made" = '3'

Question: What class had 1 made and fleet number of 406?
SQL: SELECT "class" FROM soo_line_locomotives_3 WHERE "quantity_made" = '1' AND "fleet_number_s" = '406'

Question: What class has 0 preserved and 2 made?
SQL: SELECT "class" FROM soo_line_locomotives_3 WHERE "quantity_preserved" = '0' AND "quantity_made" = '2'