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E:\Working\Brother_Education\Preparatory_Stage_Maths-4\Open_Files\Chap-12
\\October 31, 2023 4:02 PM Bharat Arora P-5 Reader _________________________ Date: ___________________

Knowledge Desk
Greenwich Mean Time or GMT is the clock time at the According to the GMT
Royal Observatory in Greenwich, London. Country Difference with GMT
It is an international standard time format. India +5 hours 30 minutes

The differences between GMT and corresponding local Italy +1 hour
time in different countries are shown in the table Iraq +3 hours
given alongside.
China +8 hours
Egypt +2 hours

example 1: A train is departure from platform 1 at 1545. Write the time in 12-hour
clock format.

Solution: To convert the 24-hour clock time between 1300

hours to 2359 hours into 12 hours clock format,
subtract 1200 hours and write the time using p.m.

So, 1545 hours = 1545 – 1200
= 345 = 3:45 p.m.

Thus, the train departure at 3:45 p.m.
example 2: Maya goes to school at 7:30 a.m. in the morning. Write the time in 24-hour

clock format.

Solution: To write the 12 hour clock format, that is, a.m. time
into 24-hour clock format, we just remove ‘:’ sign
and write the same time without a.m.

So, we write 7:30 a.m. as 07:30 hours or 0730 hours

in the 24-hour clock format.
Practice time 12c

1. Convert the following 24-hour clock time into 12-hour clock time.

(a) 0320 hours (b) 0428 hours (c) 0937 hours (d) 1429 hours

(e) 1330 hours (f) 1740 hours (g) 1825 hours (h) 0000 hours

(i) 2222 hours (j) 2138 hours (k) 1348 hours (l) 2000 hours
2. Convert the following 12-hour clock time into 24-hour clock time.

(a) 1:40 a.m. (b) 4:57 a.m. (c) 12:06 a.m. (d) 6:05 a.m.
(e) 10:24 a.m. (f) 7:36 p.m. (g) 12:15 p.m. (h) 2:17 p.m.

(i) 11:00 p.m. (j) 12:00 midnight (k) 3:30 p.m. (l) 9:40 p.m.

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