CREATE TABLE table_24381 ("No." FLOAT, "Date" TEXT, "Tournament" TEXT, "Winning score" TEXT, "To par" TEXT, "Margin of victory" TEXT, "Runner ( s ) -up" TEXT)

Name the number for margin of victory being 3 strokes
SELECT COUNT("No.") FROM table_24381 WHERE "Margin of victory" = '3 strokes'
SELECT COUNT("No.") FROM "table_24381" WHERE "Margin of victory" = '3 strokes'