Mark M. answered • 09/09/16
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Two hours: 07:00 and 17:00
For each hour 6: 0:07, 0:17, 0:27, 0:37, 0:47, 0:57
24(6) + 2 = 146
Mark M.
Perhaps you shall be kind enough to point out my error?
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09/09/16
Ishrat Z.
so for 22 hour (not counting 7am/pm) there are 132 times 7 is shown (6 times every hour and multiply that by 22)
in 7 am/pm it is listed 13 times each so it is 26 times for both hours (7 00, 7 07, 7 17, 7 27, 7 37, 7 47, 7 57)
after u add those together u get 158
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09/09/16
Mark M.
I agree with the calculation for the 22 hours.
For the 7 am/pm would there not be 120? 7:01, 7:02, 7:03, .... twice?
So the total would be 132 + 120 = 252?
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09/09/16
David W.
The answer 146 counts all the "time readings" where the 24-hour digital clock
changes one of the digits from 6 to 7 then from 7 to 8. This is assumed to be
one count of a 7 appearing (then disappearing).
If you count both 7's in 7:07, 7:17, etc. [note: they are both "new" in 7:07, but only one of them is "new" in all the rest of those times], then to be consistent, you should count 7:00, 7:01, 7:02, etc. as different "time readings" where a 7 appears.
So, I would say that 158 is never an acceptable answer to this problem.
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09/10/16
Mark M.
The condition is "different" times, and 7:01 is different from 7:07.
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09/10/16
Ishrat Z.
thank you i believe u r right
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09/10/16
Mark M.
You are welcome.
If you are the one who did a "thumbs down" for my solution, would you kindly remove it?
Thank you.
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09/10/16
Ishrat Z.
09/09/16