Miscellanea

 

Here is a simple math puzzle that us early-onset dementia sufferers are having trouble with.  If the nine digits were actors, what's the minimum number of actors it would take to be able to represent, in turn, all the dates in the twentieth century (that is, 1900 - 1999)?  Note:  each actor can represent only one digit, and nobody can double, but only four need to be on stage at any time; for instance, "1900" would require one person to be 1, another to be 9, and two people playing zeroes.) ...