CREATE TABLE table_20742 ("Home team" TEXT, "Home team score" TEXT, "Away team" TEXT, "Away team score" TEXT, "Ground" TEXT, "Crowd" FLOAT, "Date" TEXT, "Time" TEXT)

How many crowd sizes were recorded at the game when the home team scored 7.8 (50)?
SELECT COUNT("Crowd") FROM table_20742 WHERE "Home team score" = '7.8 (50)'
SELECT COUNT("Crowd") FROM "table_20742" WHERE "Home team score" = '7.8 (50)'