CREATE TABLE table_70840 ("Year" FLOAT, "Entrant" CLOB, "Chassis" CLOB, "Engine" CLOB, "Points" FLOAT)

Which is the latest year that has an engine of Offenhauser l4, a chassis of Kurtis Kraft 500c, and the entrant of Federal Engineering?
SELECT MAX("Year") FROM table_70840 WHERE "Engine" = 'offenhauser l4' AND "Chassis" = 'kurtis kraft 500c' AND "Entrant" = 'federal engineering'
SELECT MAX("Year") FROM "table_70840" WHERE "Chassis" = 'kurtis kraft 500c' AND "Engine" = 'offenhauser l4' AND "Entrant" = 'federal engineering'