The video that I want to see is 11:09 minutes long. I want to it to finish at midnight, so what time do I have to start it?

11:48:51 p. m.

Step-by-step explanation:

11:09 minutes means 11 minutes and 9 seconds.

You need to subtract 11 minutes and 9 seconds from midnight. Midnight means 12 hours, 0 minutes, and 0 seconds.

12:00:00 - 00:11:09 =

Start with midnight written as 12 hours, 0 minutes, 0 seconds, or 12:00:00.

Now, you borrow 1 hour (as 60 minutes) from 12 making it 11:60:00.

Then you borrow 1 minute (as 60 seconds) from the 60 minutes making it 11:59:60. 11 hours, 59 minutes, and 60 seconds is the same as midnight. Now you can do the subtraction.

= 11:59:60 - 00:11:09

Subtract 0 hours from 11 hours giving you 11 hours.

Subtract 11 minutes from 59 minutes giving you 48 minutes.

Subtract 9 seconds from 60 seconds giving you 51 seconds.

= 11:48:51

You must start at 11:48:51 p. m.

Answer: 11:48:51 is the correct time to start watching.