A clock has Hour and Minute hands of the same length and NO NUMERALS on its face.
At what time between 6 O'clock and 7 O'clock will the time on the clock appear to be the same when the reflection of the clock is read on a mirror?
Source: Lewis Carroll
(In reply to
for the full 12 hours by Charlie)
Charlie:
Your list omits 0:00.000000 (ie, midnight and noon)
If you include that, then it is clear that this happens 13 times in 12 hours, so every 12/13 of an hour. Between 6 and 7, it happens at
7*(12/13) hours, which equals 84/13 hours = 6+6/13 hours.