Thanks for the question! So we’re told in this question that the M visit has both Q and V. Interestingly enough, Q has a rule prohibiting certain people from going after it, and V has a rule prohibiting people from going after it as well. Because of those two rules, M can’t be the last site visited, since R and T have to go after Q. This creates two possibilities: either M is visited first or M is visited third. Let’s say M is visited first. That means that we know that S also has to visit M on the first day, since S can’t go after V. That leaves both R and T possible, with one visiting F on the second day and the other visiting H on the third day (since F always goes before H). We can actually stop at this point, since this shows that (E) is possible—M happens before F here, since M goes first. To help visualize, this looks like (first at the top, last at the bottom):
M: SVQ F: R/T H: R/T
The other possible scenario (in case you’re curious) is where M goes second. We know Q and V visit M, and since S can’t go before V, it could either visit M or F. But if S visits M, then one of R or T has to visit F, which would put it before Q, which we can’t have. So we know that S has to visit F, and R and T have to visit H. So this scenario looks like:
M: S F: QV H: TR
 Hope this helps! Feel free to ask any further questions you might have.
LisamJanuary 27, 2021
Hello, I get that that she explained two of the plant site options for the scenarios M, F, H and F, M, H; how come she didn't add the third scenario which is F, H, M? I don't understand how she didn't count that in, or is that just going too far in the game and she just kept it at the two scenarios?
