Answer:
There are 17.4 minutes of commercials are shown each hour.
Explanation:
An hour has 60 minutes.
So in 3 hours, there are 3*60 = 180 minutes.
The commercials show 29% of the time.
So we have 0.29*180 = 52.2 minutes, in total, of commercial.
Per hour, we have 52.2/3 = 17.4 minutes of commercial.