Cube counting

[RCT PC CRN]

Please see the attached file.

Don't you think you need at least one cube at the bottom on either side of that back column in order for that column to be connected with rest of the figure via side of the cube instead of the corner edge?

I have pointed out the position of the possible cube with arrows in the figure. If the Corner edge rule is there, then you need at least one cube at the bottom either right or left of that back column. Then total number of cube will be 21+1 = 22.

This is the figure from Kaplan and they take it as 21 cube.

Somebody here (SDN) mentioned earlier that there is a rule where you need to have cube connected via side of the cube instead of corner edge.

Could someone please clarify that rule for me.

I might be going bit crazy with this thing but I'm stuck and I need bit of clear understanding here.

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[LiteBear2011]

the picture was a little unclear when I viewed the downloaded version.
I think there is 21

Thinking back to front and left to right

The furthest back row has 2 columns of 3 blocks (6)
The second furthest back row has 2 columns of 3 blocks and 1 of 2 (8)
The front row has 3 blocks (3)

The second row gets tricky.
There is definitely 1 column of 2 blocks (2)
It looks like only 2 blocks, with a space in the middle (2)
It is clearly a space, since you can see lines that indicate outline of the bottom block of a 3 block column.

I don't think the "must be connected by a face" rule is true.

Sum: 6+8+3+2+2 = 21

 

[Kaka89]

I got 21 cubes as well.
The rule that I know of is "what you see is there and what you don't isn't" UNLESS there is a cube below another one in order to SUPPORT the one above. I don't think you need to put any cubes in the spaces you drew the arrows because those cubes will not support any other cubes in the figure. Hope this helps and good luck studying!

 

[Member 8586]

bump for this old question...can someone verify the rules? i know that if you dont see the cube, you assume its not there, unless its a supportive cube.....but i also thought all the cubes have to be connected as well like the OP mentioned?

 

[chill45]

bump for this old question...can someone verify the rules? i know that if you dont see the cube, you assume its not there, unless its a supportive cube.....but i also thought all the cubes have to be connected as well like the OP mentioned?

The first rule is definitely the case. The second rule you mention I have never heard of, and technically all the cubes are connect because the corners are still touching.