The movie that is being replayed 6 times takes 1.5 x 6 = 9 hours. The advertisements before the start of the movie take 20 x 6 = 120 minutes in all. One hundred twenty minutes is equal to 120 / 60 = 2 hours. Thus, the movie theater operates for 9 + 2 = 11 hours each day.
This justifies what answer for what question? Q & A:
A movie that's 1.5 hours long is being replayed 6 times in one movie theater each day. There is a 20-minute advertisement before the start of the movie. How long, in hours, does the movie theater operate each day?
11