Problem 1
1:47:54 PM converts to 13:47:54 in the 24 hour clock format.
Simply add 12 to the hour value. The other values stay the same. This applies to PM time values only.
As another example, 3:04:12 PM = 15:04:12
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Problem 2
Start = 1:47:54 PM
End = 2:00:00 PM
The gap from 54 seconds to 60 seconds is 6 (since 60-54 = 6)
If we let 6 seconds elapse then we go from 1:47:54 PM to 1:48:00 PM
Then we'll need to let an additional 12 minutes elapse to go from the 48 minute marker to the 60 minute (aka 1 hour) marker.
We can think of it like this
1:47:54 PM
+ 0:12:06
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2:00:00 PM
Answer: 12 minutes and 6 seconds