CREATE TABLE table_name_3 (class VARCHAR, length VARCHAR, circuit VARCHAR)

Which class was on the Las Vegas Motor Speedway for 2 hours?
SELECT class FROM table_name_3 WHERE length = "2 hours" AND circuit = "las vegas motor speedway"
SELECT "class" FROM "table_name_3" WHERE "2 hours" = "length" AND "circuit" = "las vegas motor speedway"