CREATE TABLE table_8108 ("Result" TEXT, "Race" TEXT, "Distance" TEXT, "Weight" FLOAT, "Winner or 2nd" TEXT, "Pos'n" TEXT)

What is the weight when the race was the VRC Melbourne Cup?
SELECT COUNT("Weight") FROM table_8108 WHERE "Race" = 'vrc melbourne cup'
SELECT COUNT("Weight") FROM "table_8108" WHERE "Race" = 'vrc melbourne cup'