A cube with edge length 7 units is painted on all faces. It is then cut into 7
^{3} unit cubes. These cubes are put in a bag, one is chosen at random and rolled.
What is the probability the side that faces up is painted?
There are 7^3 cubes, each with 6 sides, so there are 7*7*7*6 faces that each have the same probability of being the upturned face.
There are among them 7*7*6 faces that are painted.

Posted by Charlie
on 20191106 10:31:12 