The problem is underspecified. Digital clocks may run from
(a) 1:00 to 12:59 (b) 01:00 to 12:59 (c) 0:00 to 23:59 (d) 00:00 to 23:59 (e-h) any of the above with seconds appended, :00 to :59.
I agree that not all of these are common, but I have seen some uncommon ones. For that matter, I've seen ones not on the above list -- the Toronto subway stations used to contain digital clocks that ran from 0:00 to 12:59 (pm), then from 1:00 (pm) to 11:59 (pm), while a computer that I used to use had the inverse anomaly -- its time of day command displayed times from 12:00:00 to 12:59:59 (am), then 01:00:00 to 23:59:59!
I get the following results for the 8 cases.
CASE AM+PM HOURS pals/hr TOTAL OVERALL TOTAL (a) yes 1-9 6 54
10-12 1 3 114
(b) yes 01-05 1 5
06-09 0 0 10-12 1 3 16
(c) no 0-9 6 60
10-15 1 6 16-19 0 0 20-23 1 4 70
(d) no 00-05 1 6
06-09 0 0 10-15 1 6 16-19 0 0 20-23 1 4 16
(e) yes 1-9 60 540
10-12 6 18 1116
(f) yes 01-05 6 30
06-09 0 0 10-12 6 18 96
(g) no 0-9 60 600
10-15 6 36 16-19 0 0 20-23 6 24 660
(h) no 00-05 6 36
06-09 0 0 10-15 6 36 16-19 0 0 20-23 6 24 96
--Mark Brader (msb@sq.com)