Answer :
To convert time from a 24-hour clock to a 12-hour clock format, follow these simple rules:
- If the hour is greater than 12, subtract 12 from the hour and add 'p.m.'.
- If the hour is less than or equal to 12 and not zero, add 'a.m.' if it's before noon, or 'p.m.' if it's noon or after.
- If the hour is 0, convert it to 12 a.m.
Let's apply these rules to the given times:
- Change the following times to 12-hour clock time:
a) 13:10- 13 is greater than 12, so we subtract 12 to get 1
- The time is 1:10 p.m.
b) 09:45
- 9 is less than 12, so it's in the morning
- The time is 9:45 a.m.
c) 22:30
- 22 is greater than 12, so we subtract 12 to get 10
- The time is 10:30 p.m.
d) 04:05
- 4 is less than 12, so it's in the morning
- The time is 4:05 a.m.
- A DVD recorder uses 24-hour clock time:
a) What time is shown on the DVD recorder at 7:30 p.m.?
- 7:30 p.m. in 24-hour format is 19:30
b) The DVD recorder is set to record programmes from 11:10 to 16:40.
- 11:10 is less than 12, so it is 11:10 a.m.
- 16:40 is greater than 12, so we subtract 12 to get 4:40
- The time is 4:40 p.m.
In summary, converting between 24-hour and 12-hour time formats involves adjusting hours for p.m. times and adding appropriate a.m. or p.m. markers based on the time of day. This is a common skill used in various real-life situations, such as reading timetables and setting electronic devices.