math
posted by j on .
a cube with 2 in sides is placed on a cube with 3 in sides. then a cube with 1 in sides is placed on the 2 in cube. what is the surface area of the three cube tower?

5 sides of the top cube is exposed.
so we get 1*1 * 5 = 5 in ^2
the second cube has 4 sides exposed also, so 2^2 * 4 = 16 in ^2, but also it has one side with the cube on top, so we have 41 = 3 on that side, so the overall is 19 in ^2
Then we have for the third cube 5 sides exposed, so we have 3^2 * 5 = 45. We also have the area of the 2in cube on it, so we get 3^2  2^2 = 94 =5.
So the overall is 45+5+19+5 = 55+19 =74 if i am not mistaken...