A man has two cubes on his desk. Every day he arranges both cubes so that the front faces show the current day of the month. what numbers are on the faces of the cubes to allow this?See Solution : Calendar cube
So that means we need to have 0 on both the cubes, but that makes it 13, but there are only 12 faces. Thats the trick in this question, we can place cubes upside down too, now which is the number we can use both the ways, yes its 6, it can be used as 9 and then we can have all the possible dates.
so first cube : 0, 1, 2, 3, 4, 5
second cube : 0, 1, 2, 6, 7, 8
Balls in a bag