Question

Helena is watching a movie on television she notices that there are 9 1/4 min of commercial for every 1/2 hour of the movie

Answer 1

If Helena watches a movie that shows a commercial for 9 1/4 mins of every 30 minutes (half hour), then the unit rate of commercials per hour is derived as;

`\begin{gathered} \text{Com /30 mins=9}(1)/(4) \\ \text{Com /60 mins=9}(1)/(4)*2 \\ \text{Com /hour=}(37)/(4)*2 \\ \text{Com /hour=}(37)/(2) \\ Com\text{ /hour=18}(1)/(2) \end{gathered}`

The unit rate of commercials per hour is 18 1/2 minutes (eighteen and half minutes)