CREATE TABLE table_20731 ("Home team" TEXT, "Home team score" TEXT, "Away team" TEXT, "Away team score" TEXT, "Ground" TEXT, "Crowd" FLOAT, "Date" TEXT, "Time" TEXT)

The away team of Richmond played on what grounds?
SELECT "Ground" FROM table_20731 WHERE "Away team" = 'Richmond'
SELECT "Ground" FROM "table_20731" WHERE "Away team" = 'Richmond'