neoking77

10+ Year Member
Jul 7, 2007
82
25
Status
Hi guys,

I have a question -- for this cube counting question, how are we supposed to know whether that 2-sided cube (Red -- hidden behind the tower) is there or not? I thought it would be empty space, but it appears I'm wrong. What is the rule when it comes to these ambiguous situations?


Thank you!
 

StevenLuSL

7+ Year Member
Sep 18, 2012
171
175
Status
Dental Student
In the ADA rules it says:

Each figure has been made by cementing together cubes of the same size. After being cemented each group was painted on all sides except for the bottom on which it is resting. The only hidden cubes are those required to support other cubes. You are to examine the figure closely to determine how many cubes have:

So basically, cubes can't just connect to each other by corners, they must connect by their faces.