CREATE TABLE table_18635 ("District" TEXT, "Incumbent" TEXT, "Party" TEXT, "First elected" FLOAT, "Result" TEXT, "Candidates" TEXT)

how many dbeingtrict with candidates being william b. bankhead (d) 71.3% e. m. reed (r) 28.7%
SELECT COUNT("District") FROM table_18635 WHERE "Candidates" = 'William B. Bankhead (D) 71.3% E. M. Reed (R) 28.7%'
SELECT COUNT("District") FROM "table_18635" WHERE "Candidates" = 'William B. Bankhead (D) 71.3% E. M. Reed (R) 28.7%'