 Hello and welcome to the session. In this session we shall discuss the following question and the question says that a box has one red ball, one green ball and one blue ball. Two balls are drawn from the box one after the other Without replacing the first ball drawn, use the tree diagram to find the number of possible outcomes for the experiment. Find the probability of drawing a green ball in the first draw and red ball in second draw. We know that probability of any event say A is given by probability of event A is equal to favorable outcomes. Again, total outcomes. This is the key idea we are going to use in this question. Let us move on to the solution. Now in this question we use tree diagram to write sample space of outcomes of the two balls drawn without replacement. In the first draw we may draw a red ball or a blue ball or a green ball. If we draw a red ball then we are left with one blue ball and one green ball and we can draw either of them in second draw as we do not replace the ball drawn in the first draw. Similarly if we first draw green ball then we are left with one blue and one red ball and we can draw either of them in the second draw. Similarly if we draw a blue ball in the first draw then we are left with one red and one green ball and we can draw either of them in the second draw and so we have the following tree diagram and this is the required tree diagram. Therefore the possible outcomes are RG that is red and green ball, RB that is red and blue ball, GR that is green and red ball, GB that is a green and a blue ball, BG that is a blue and a green ball or BR that is a blue and a red ball. So the number of possible outcomes is given by 6. We need to find the probability of drawing a green ball in the first draw and a red ball in the second draw. So let event A be equal to drawing a green ball in the first draw and a red ball in the second draw. Now from the tree diagram we see the branch joining G and R which is the only favorable outcome for event A. So probability of event A would be favorable outcome upon total outcomes and here we see that we have only one favorable outcome to this event and the total number of outcomes is given by 6. So we get the probability as 1 by 6 that we say that probability of drawing a green ball in first draw and a red ball in second draw is given by 1 upon 6 which is the required answer. This completes our session. Hope you enjoyed this session.