Q5

User avatar
 
noah
Thanks Received: 1192
Atticus Finch
Atticus Finch
 
Posts: 1541
Joined: February 11th, 2009
 
This post thanked 4 times.
 
 

Q5

by noah Fri Nov 19, 2010 2:32 pm

A student was confused by #5 and #6, so here are some quick explanations:

#5: We're looking for what cannot be true. We can expect some time-consuming wrong answers, and hopefully an obvious right answer.

(A) LG or GL. This seems ok. LG - P can fit towards the back of the line.
(B) RP. Hmm, that seems impossible. If R is first, where would the G go that needs to come before P?

(B) is the answer and during the test there's no need to check the other answers, which, of course, are all possible.

#6: We want something that can't be next to R. Tough question. One technique is to use previous work. For example, #1 tells us that P can be next to R. So (C) is gone.

Now let's look at what's left. We want to consider answer choices which seem likely to have a problem being in slot 2 and in slot 5 (the only slots that put you next to R). In numbered ordering, always start by considering the chunks. There's really only the SL chunk (and both are answer choices). Could L be in 2 or 5? Yes, it could be in 5: GPWSLR. So, what about S? It can't be in slot 2 since then there'd be someone other than S or W in slot 3. And it can't be in slot 5, because where would L go? (S would be in slot 5 in this scenario to be next to R in slot 6, where L should go.) So, (D) is our answer.

Make sense?

By the way, I haven't played this game in a long time and I made the same mistake I made about 6 months ago when I last played it: I wrote LS instead of SL. I've got to be careful with that!

I hope that helps.