Setup and Rule Diagrams

[Dave Killoran]

Awesome, so glad I could help!

[downeyy17]

Hi Dave,

I just completed the Dinosaur game on my own and then watched your video on how you set up the game. I'm happy to say my set up was practically the same as yours so at least I'm doing something right However, for the Mauve dinosaurs, my diagram is a little different as I made an additional inference and I'm not sure if it's correct.

My diagram looked as follows:

Color: M----------M---------R--------G/Y------___
Dino: T/V-----L/U/T/V-----S---------I/P-------___

I played around with it a bit and came to the conclusion that one of the Mauve dinosaurs must be either T or V. So from that, I had the inferences that if V is not included, then there must be a mauve tyrannosaur. And if T is not included, there must be a mauve velociraptor (and the other mauve dinosaur is L). Are these inferences justified to make?

I also found that L & U couldn't both be included, and both not be mauve. So although the rules say, "If both L and U are included, at least one of them is not mauve", I found that ONLY one could not be mauve. Thus, either I or P is included.

I was able to answer all of the questions correctly with these inferences, but I want to know if they are justified to make. Also, for reference, I completed the game in about 12 and a half minutes.
Thanks for all your help!

[Nikki Siclunov]

Hi downeyy17,

Dave is out of town today, so I thought I'd jump in and respond to your question.

Your inferences are spot-on:

1. Since you can't use both U and V, at least one of the two dinosaurs that aren't included must be either U or V. Therefore, you can't exclude both I and P, suggesting that at least one of them must be included. So, yes - you need to have either I or P (or both).

2. I wouldn't diagram the possibilities for the two Mauve dinosaurs the way you did: it makes it look like you can have two T's, which is obviously not possible. Since the two Mauve dinosaurs are functionally identical, I'd try to figure out what combinations of two Mauve dinosaurs are allowed by the rules. These are: LV, LT, TU, TV. That's it. And yes, at least one of T or V must be mauve.

Personally, I suspect this level of inference-making is partly the reason why you took so long on this game: you may have gone a bit too far. All I would do on this game is focus on the most restrictive rule, which is the fact that exactly two of the chosen dinosaurs must be Mauve. Since the rule prohibit I and P from being Mauve, and also prohibit both L and U from being Mauve, and you can't use both U and V anyway, there must be a finite number of possible combinations here. I would do that, notate that either U or V must be excluded, and move on to the questions

That said, good job with that set-up. It's a killer!

[LSAT2018]

When the rule says If both the lambeosaur and the ultrasaur are included, at least one of them is not mauve, does this mean that at least one of them is mauve?

[Jon Denning]

No! It's simply ruling out both. It's possible (in theory at least based on the language of just this rule) that neither is mauve!

[rbrar_71]

Hello,

I set up this game in a different way and I wanted to check if this was okay. I made four templates: one where L and U are both in, one where L is in with U/V both out, one where L and V are in, and one where U is in with L out. I believe these 4 templates cover all the possibilities within the game.

I was able to answer the questions very quickly and with precision using the templates. Of course, I only used this method after struggling with the questions on a timed practice. Is this method too time consuming for this game to use?

Thank you!

[Adam Tyson]

I do like a good template approach, rbrar_71, but it needs to be complete, and it appears to me that you missed one template doing it this way: what about L and U both being out? It would be the same as when L and V are both out, just swapping the U and V, but you have to be sure not to miss that combo!

Perhaps think of it this way: L and U (if you choose to work with them, since they have that special rule about mauve, which seems wise) have 4 options, as follows:

1) Both in (V is out; one of L or U is not mauve, so either I or P must be out)
2) Both out (Everything else must be in)
3) L in, U out (in which case V may or may not be in)
4) U in, L out (V is also out because of U, so everything else must be in)

I chose a different approach, doing templates around which pairs could be mauve, which are:

LT
VT
UT
LV

You did some good thinking there, and I like where you went with it, but just be sure that your choice for templates is comprehensive enough to catch every possible solution within them.