If the team works at Grayson mine in July, which one of the following could be true?

aseikhon11 on July 29, 2020

looking at the possible 4 options, we would be in the #3 option? Which is the only option where Grayson is in July. GHKHGGHKK? for the other combinations (1,2 & 4) Headquarters would be in July? No? MAMJJASON Option 1: GGHKHGHKK Option 2: KHGGHGHKK Option 3: GHKHGGHKK Option 4: KHGGHGHKK

shunhe on July 30, 2020

Hi @anchelle,

Thanks for the question! So as for how (D) can be right: is it possible for them to work at K in March, and then G in July? Well, let’s find out. Let’s say that they do work at K in March. Then we’re going to have

K _ _ _ _ G H K _

And we know that September is an H since H has to happen between working different mines, and the other G and K follow directly from the rules. Let’s put our last K next to one of the other ones. We’ll just stick it in November for now:

K _ _ _ _ G H K K

So now we have two Gs and 2 Hs left to fill in the last slots. Well, slot 2 has to be an H, since K and G can’t be next to each other.

K H _ _ _ G H K K

And then if we put the other H next to the first, we get 3 Gs in a row, which is a no-go. So we have to put a G there.

K H G _ _ G H K K

And then for the last two slots, it looks like we can put H in either one, and G in the other. So it’s

K H G G/H H/G G H K K

which means that the ordering

K H G H G G H K K

works, and that has G in July. I think you would’ve gotten this, but your options 2 and 4 are the same for some reason. So you might have just written one of them down incorrectly.

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