If the Morningside visit includes both Quinn and Vandercar, which one of the following could be true?

Ryan on April 20, 2019


again how do you come up with these deductions? like how is this question becoming a two world scenario? I really dont get it. super frustrating

1 Reply

Shunhe on January 12, 2020

Hi @maybeillgetlucky,

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):

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

Hope this helps! Feel free to ask any further questions you might have.