There are 8 marbles in a bag. 4 marbles are red. 3 marbles are blue. 1 marble is green. On marble is selected at random from the bag. (a) On the probability scale mark with a cross (X) the probability that the marble is red. 1 1 ! (b) On the probability scale mark with a cross (X) the probability that the marble is yellow.. + (c) Write down the probability that marble is blue.