CREATE TABLE table_18418 ("District" TEXT, "Incumbent" TEXT, "Party" TEXT, "First elected" FLOAT, "Result" TEXT, "Candidates" TEXT)

In which district is the incumbent Carl W. Rich?
SELECT "District" FROM table_18418 WHERE "Incumbent" = 'Carl W. Rich'
SELECT "District" FROM "table_18418" WHERE "Incumbent" = 'Carl W. Rich'