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

Maria-Marin on July 13, 2020

Hey!! could you please explain me why Answer choice A could not be correct?

shunhe on July 14, 2020

Hi @Maria-Marin,

Thanks for the question! So we’re asked which one of the following could be true if we put G in May. And that means that four of these answers must be false. Now let’s take a look at (A). Is it possible that the team works at the Grayson mine in March?

Well, if this is true, then we know the following

G _ G _ _ G H K _

We know that the team works at G in August from the second to last rule, at K in October from the last rule, and there has to be an H in between based on the first rule.

So now remember that the team works 3 months at G and 3 months at K, and there are 9 total months, so 3 months are also at H. So what do we have left to place? Well, we’ve placed all our Gs and an H and a K, so we have to place 2 more Hs and 2 more Ks.

So let’s focus on where we can put those two Ks. Remember the first rule; the team has to work at least one month at headquarters between working at different mines. Basically, that means that K and G can never be next to each other. So we can’t have a K in April, June, or July. So the only place we could put K is in November. But we have to place two Ks! So this set up is impossible, and it’s impossible to have G in March if we have G in May.

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