Mental Floss

Brain Game: It's a Date!


I remember when I got my first "desk" job... My desk had a funky calendar that was really nothing but two cubes and a little stand to place the two cubes side-by-side for the date. I also used a manual typewriter, but that's just showing my age.

Anyway, this two-cube calendar didn't indicate the month or the day of the week; just the date. Each of the six sides on the two cubes depicted a single digit. By placing some combination of the two cubes in the slots on the stand, you could indicate any date from 01 to 31. (You had to keep a cube in each slot... you wouldn't want to hide one of them and lose it.)

Today's question (and it's probably a bit trickier than it seems at first glance):

What were the digits on the sides of the two 'date' cubes that allowed every possible date to appear using both cubes?

Here's one SOLUTION.


One of the cubes had the digits: 0, 1, 2, 3, 4, and 5.

The other cube had the digits 0, 1, 2, 6, 7, and 8.

By using some combination of the two cubes -- and placing the '6' cube upside down for the '9' when necessary -- you could use these two cubes to indicate any date from 01 to 31.