Watch which loses a half minutes every hour was set to reach the correct time at 05 45h on Monday. Determine what time in the 12 hour system the watch will show on the watch will show on the following Friday at 1945h
First, let's calculate how many days have passed from Monday to Friday:
Friday is 4 days after Monday.
Next, let's calculate how many minutes the watch will lose during this time:
1 hour = 60 minutes
1 day = 24 hours
1 day = 24 * 60 = 1440 minutes
The watch loses 0.5 minutes every hour, so it will lose 0.5 * 1440 = 720 minutes in a day.
Therefore, in 4 days, the watch will lose a total of 4 * 720 = 2880 minutes.
Now, let's calculate the time on Friday at 19:45h in the 12-hour system, taking into account the time lost by the watch:
Adding 2880 minutes to 19:45h on Friday gives us 19:45 + 2880 minutes = 19:45 + 48 hours = 19:45 + 2 days = 19:45h on Sunday.
Therefore, the watch will show 19:45h on Sunday in the 12-hour system.