Question: What is the total number in class for the Whitehaven Coal?
SQL: SELECT SUM("Number in class") FROM "2-17557270-1" WHERE "Owner" = 'Whitehaven Coal';

Question: What was built in a class with less than 10, and the Downer Rail owner?
SQL: SELECT "Built" FROM "2-17557270-1" WHERE "Number in class" < 10.0 AND "Owner" = 'Downer Rail';

Question: Which class has more than 15 people in the class?
SQL: SELECT "Class" FROM "2-17557270-1" WHERE "Number in class" > 15.0;

Question: Who is the owner that built in 2009-2011?
SQL: SELECT "Owner" FROM "2-17557270-1" WHERE "Built" = '2009-2011';