Cube Counting Pic- I thought you only assume unseen cubes that hold others up.

[Jay0689]

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Crack DAT PAT says this stack has 5 cubes with 3 painted sides. For this to be true, it seems that you would have to assume that there is unseen cube in the SECOND level behind the tower.

I know you would have to assume that there is an unseen cube in the first level in order for the stack to remain connected, but why do you assume the 2nd story one?

 

[mh0000]

honestly, I haven't review the cube counting rules yet, but can those cubes on the second level float like that? I would think there woyuld need to be a level of cubes below to support them

 

[herkulease]

I constructed what the thing actually looks like last year. take a look and it'll help you out. what you're seeing is an illusion.

http://forums.studentdoctor.net/showpost.php?p=9751151&postcount=11

 

[mh0000]

I constructed what the thing actually looks like last year. take a look and it'll help you out. what you're seeing is an illusion.

http://forums.studentdoctor.net/showpost.php?p=9751151&postcount=11

AH crap, you're right. Lol, looks like I need to start practicing cube counting. Are they this tricky on the real thing?

 

[herkulease]

AH crap, you're right. Lol, looks like I need to start practicing cube counting. Are they this tricky on the real thing?

Nope. its is very straight forward on the actual exam. No illusion. No debates about whether this is really there or not, is this touching etc.

the setup in terms of # of cubes is not huge either. I remember CDP has some that were huge.

 

[Jay0689]

Ok thanks for the help. However, I realize (I think) that the cubes are not floating and how they are really layed out, but still for your model to be right, you are assuming 2 unseen cubes in the back row, levels 1 and 2. Am I right that you are assuming those are there?

 

[es1113]

In OP's, I'm counting 10 cubes. In the second one, I counted 12 and it looks like a different figure altogether. I got three cubes that had 3 painted sides on OPs. There definitely has to be unseen cubes if the thing about 5 cubes with 3 painted sides is true.

 

[rockclock]

In OP's, I'm counting 10 cubes. In the second one, I counted 12 and it looks like a different figure altogether. I got three cubes that had 3 painted sides on OPs. There definitely has to be unseen cubes if the thing about 5 cubes with 3 painted sides is true.

they're the same figure. there's 12 cubes total. there are 2 unseen cubes that you have to assume are in the back "wall" for continuity.

 

[es1113]

intredasting.... well, most likely won't have to deal with ambiguous structures so s'all good

 

[Jay0689]

Rock clock and Herkulease, I do appreciate your model and explanation, which is how I saw the figure anyway, but you're not explaining why you have to assume the 2nd unseen cube (in the second level) must exist. That was my question.

Are you saying that it must exist because you have to assume the second level is continuous? This does not seem consistent with the rule that you only assume unseen cubes exist if they are required to hold up another cube.

 

[slingshot2004]

actually the second row in the back has only one cube, the one to the right, there are no cubes to the left of it...if you can't see it don't assume it's there, unless it's supporting another cube...🙂

 

[herkulease]

Rock clock and Herkulease, I do appreciate your model and explanation, which is how I saw the figure anyway, but you're not explaining why you have to assume the 2nd unseen cube (in the second level) must exist. That was my question.

Are you saying that it must exist because you have to assume the second level is continuous? This does not seem consistent with the rule that you only assume unseen cubes exist if they are required to hold up another cube.

It is true there could be a missing cube there it you could still have it as 1 cemented setup. but there are certain assumptions you just have to make. while it isn't exactly one of the rules of hidden cubes it would be impossible if it was situated like cdp but then say well its not continuous there's a missing cube. There's no way for you to tell.

as I noted and maybe rockclock noted you will not get anything like this on the actual test. It will be crystal clear whether it is continuous or not. they are not out to trick you. Pull up the free sample ADA to get an idea of how simple it is.

 

[rockclock]

actually the second row in the back has only one cube, the one to the right, there are no cubes to the left of it...if you can't see it don't assume it's there, unless it's supporting another cube...🙂

oh I see what you're getting at. I'm pretty sure the caveat to the either-see-it-or-need-it-for-support rule is that unseen portions match seen portions. basically the same idea as keyholes...you assume that the back corner you can't see is the same as the other three you can, for example, otherwise keyholes would be impossible.

in any case, herkulease's take home message was key...the real DAT won't throw these ambiguous cases at you. actually, if I remember right, in a lot of cases the cubes are show from an angle such that they don't line up exactly the way they do in CDP. that way, one column would never completely obscure another.

 

[Jay0689]

Ok thanks guys! That was more what I was looking for.