Solution
For this case we need to find the number of cubes in the stack given so then we can do this:
The first line present 5 cubes
The second line present 5 cubes
And the last line we got:
10 cubes
Then the total of cubes are:
10 +5+5 = 20 cubes
If we need to find the number of faces we can do the following:
5+ 4+ 4+4 +4 +1 + (5+4+4+4+4+1 ) + (5+4+4+4+4+1 ) + (5+ 4+4+4 +4 )
And solving we got:
22+22+ 22+21= 87
