CREATE TABLE table_73193 ("LMS No." FLOAT, "WD No." FLOAT, "Builder" TEXT, "Serial No." FLOAT, "Date built" FLOAT)

Name the total number of serial number for 24 wd no
SELECT COUNT("Serial No.") FROM table_73193 WHERE "WD No." = '24'
SELECT COUNT("Serial No.") FROM "table_73193" WHERE "WD No." = '24'