Answer:
Poor Alex, I know how they feel, I got a dog myself.
The amount of time between
11:41 pm to 12:09 am is
19 minutes (to 12 am, 60 minutes to next hour) + 9
which is 28 minutes for the first dog barking session
the second time is 35 minutes,
using same method as before.
adding the two separte barking sessions we get
35+28= 63 minutes
which is equivelant to 1 hour and 3 minutes.
In conclusion the dog barks for 1 hour and 3 minutes in total.