## Q15

ShehryarB30
Elle Woods

Posts: 100
Joined: July 07th, 2018

### Q15

Could you pls explain how to do this one?

ohthatpatrick
Atticus Finch

Posts: 4257
Joined: April 01st, 2011

### Re: Q15

First, write down S - P near Q15 and then try to attach the rules you already know to that.

We knew that P is before Q and R because P is int'l and Q and R are domestic.

And we knew that R is before Q, because Getaway domestics (like R) come before Flyhigh's domestic (which is Q).

So we had P - R - Q from our setup. Now, on Q15, we have
S - P - R - Q

We know that S must be international, because P is international and you can't put a domestic before an international. So we have
..i - i - d - d
S - P - R - Q

Who's left? The floater T. T could be international or domestic, for all we know.

If it's international, it could be before S, after S, or after P.
If it's domestic, it could be before R or after R (it can't be after Q because Getaway domestics are before Flyhigh's domestic).

(A) Sure, we could do
i i i d d
STPR Q

(B) this could never happen. S will be 1st or 2nd.

From the time we had S - P - R - Q on our page, we could have known this would be false. If S has three things after it, it can't be in any of the last three spots, so its latest would be spot 2.

We could pick this answer and move on

(C) We already proved this could happen with the scenario we wrote for (A).

(D) Sure, P and T could switch in the scenario we wrote for (A).

(E) Sure, as long as we made T domestic, we could do
i i d d d
SPR T Q

hope this helps