Answer :

To convert exactly 21 days into seconds, we need to consider how many seconds are in one day first. Here’s how we can break it down:

1. Hours in a day: There are 24 hours in a day.
2. Minutes in an hour: There are 60 minutes in an hour.
3. Seconds in a minute: There are 60 seconds in a minute.

First, calculate the total number of seconds in one day:
- 24 hours/day × 60 minutes/hour × 60 seconds/minute = 86,400 seconds/day

Now, to find out how many seconds are in 21 days, we multiply the number of seconds in one day by the number of days:
- 86,400 seconds/day × 21 days = 1,814,400 seconds

So, 21 days is equivalent to 1,814,400 seconds.