1. How many primes are in a clock if you regard the numbers on its face as a continuous clockwise string of digits; not to exceed 15 digits i.e. one full round?

2.Same question for a counterclockwise direction.

3.Same question for a digital watch ((HH(0-23)MM(0-59)) - in ascending order).
________________________________________

(In reply to Interpretation, and Reference by ed bottemiller)

Let's clarify:

 

"....same question" implies   " 15 digits at most'.

Posted by Ady TZIDON on 2010-10-08 15:02:39