Solution:
Note that:
16% = 0.160

so that, the correct answer is:
16% = 0.160
0.165
1/6 = 0.17
The answer you are looking for is -5
Answer: About 3.14 inches
Since the block is a cube, the dimentions from corner to corner equal all the same, as long as the pieces are equal, which in this case, they are. :) So basically what you need to do is find the perimeter of one side of the cube, and that's the answer.