Unless you are allowed to ask questions or gain some prior knowledge, isn't the outcome of picking a black marble (given that you have to put all marbles into t

Unless you are allowed to ask questions or gain some prior knowledge, isn't the outcome of picking a black marble (given that you have to put all marbles into the bags) 50%? ~50/50 -> .5x(2/5) + .5x(3/5) = .5 ~0/1 -> .5x0 + .5x1 = .5