Question: What is the quantity preserved for fleet number(s) 3000–3015?
SQL: SELECT "Quantity preserved" FROM "2-18620528-15" WHERE "Fleet number(s)" = '3000–3015';

Question: What manufacturer has a wheel arrangement of 4-6-6-4, and a Class of Z-7?
SQL: SELECT "Manufacturer" FROM "2-18620528-15" WHERE "Wheel arrangement" = '4-6-6-4' AND "Class" = 'Z-7';

Question: What is the Year for fleet number 5000?
SQL: SELECT "Year made" FROM "2-18620528-15" WHERE "Fleet number(s)" = '5000';

Question: What year made has a Quantity made of 4?
SQL: SELECT "Year made" FROM "2-18620528-15" WHERE "Quantity made" = '4';

Question: What is the quantity preserved for the serial number of Mallet and Simple Articulated Locomotives?
SQL: SELECT "Quantity preserved" FROM "2-18620528-15" WHERE "Serial numbers" = 'Mallet and Simple Articulated Locomotives';