Question

4:00pm is called 1600 hours in 24 hour clock time

Answer 1

Midnight 00:00 and 24:00. In the 24-hour time notation, the day begins at midnight, 00:00, and the last minute of the day begins at 23:59.

Answer 2

Yes , you are right
If you wanna ask why ?
here is your answer

total time in 12 hour format = 12:00
Time = 4:00 p.m
time in 24 hour format = 12:00+4:00 =
16:00
And you can now write it as 1600