 In this video we provide the solution to question number two for practice exam number two for math 1030, in which case a Diagraph is provided to us right here, and we have to determine which of the following sequence of Vertices below is a valid path on this graph and particularly have to pay attention to that since it's a digraph We have to go with the flow. So if we go through these ones like let's just draw them out The first one here choice a so we go from f to b to c to d to a and Then from a to b You know we have to go against the edge right there that last one We're doing really good, but it's not a okay You look at the next one choice B So you go from f to b to c to d to a all right that one sounds good that that totally seems good there So it looks like the choice is going to be b But let's look at the other ones to see why they don't work the next when you go from g to d can't do that one The next one you're gonna go from b to a and then from a to d and you can't do that one Notice a is a sink all arrows point to a there's no way to get out of a once you get there the next one Oh, you can't leave a so that's gonna fail as well And then if you look at f there as a choice you go from e to d To a up you can't get out of a that's gonna be a problem So yep sure enough if you go through all of the possibilities they all fail except for choice b That's the only valid path on this digraph