a cube is made of white material, but he exterior is painted black. if the cube is cut into 125 smaller cubes of exactly the same size, how many of the cubes will have atleast 2 of their sides painted black?
Only the surface small cubes are possible to have black side(s). There are 3 kinds of surface small cubes: corner, edge, and rest. Only corner and edge ones are possible to have more than 1 black sides. There are 8 corner ones and 3 x 12 = 36 edge ones. So the answer is: 8 + 36 = 44
Well, they follow pretty regular pattern... Just look at the last message and figure out that your post will be on another color Here are tags. For "light" background: <font color="#f0e6d5">some text</font> For "dark" background: <font color="#eadbc4">some text</font>