So let's go through example number 1. I will ask you to draw an activity on arrow diagram for the following activities, and I highlighted in the second column here. What are the predecessors of each of the activity? So, as the beginning, we have activity A. As I explained, you start the project with a simple node. And from that simple node you just go with a simple arrow to highlight the first activity, A, which has starting mode and a finish node. Then, activity A has no predecessors. So it's going to be the first activity in the project. And now we have activity B, which is the predecessor for it is A. So I can say activity B will go like that. I will have a little bit bigger circle, or bigger node. And then we said activity C, the predecessors of it is only one activity which is A. So I can have another activity here, which is C, to highlight the relationship. Now we have activity D, the predecessor of it is B. Usually how I would do it, I would draw just a simple line, highlight activity D in it, without having an arrow. Because I don't know yet where is activity D heading. The following one would be activity E, and activity E has predecessors of B and C. So if that's the case, I can do the solution by having activity E. If you notice, there is a split between both of them, and if I move C to B here, then activity D will be the predecessors of both B and C. But I only have activity E has these two predecessors. So how about I make a dummy activity to C and have activity E going out from here? So in this case, I met the requirement, or the predecessors, that gave to me in the table here. Which is E that predecessors would be C, and the dummy activity here, it shows when B finishes also it finishes here, then E would start after B and C will finish. However, if we look at the last activity, which is F, the predecessors of F is C. So if I have activity F going out from here. Then that will be okay for F because once C finishes, F will start. However, I'm starting with the same node where it says B also finishes. So if that predecessors for it, in this diagram I have in front of me would be B and C, which is the wrong relationship that given to us in the exercise. So how to solve that is to also what I would use here another dummy activity. So I will delete F and I will delete E and I will take out this dummy activity here and say, okay, activity E has two predecessors, which is. B and C. So if we have E going like that, it will meet the requirement of the two predecessors of B and C. Then F, if we took it out from here, then that will satisfy our relationship between F and C without violating any relationship in our schedule. And that's the end of all the activities. So the activity D, E, and F, would the last three activities in the project then I can connect them by one node, like that. Then we have here. Our diagram, or the schedule. A, no predecessors the beginning, B has one predecessor, A, C has one predecessor A. D has one predecessor B, E has two predecessors, B and C, with two W activities. And then we have activity F with one predecessor C. And you always link all the last activities to that one last node to highlight the end of the project. After you finish, what you need to do is numbering the diagram. I can say 1, 2, 3. 4, 5, 6. So that would be our schedule.