Question

Helena is watching a movie ontelevision. She notices that there are9. min of commercials for every hof the movie.What is the unit rate of minutes of commercials per hour of the movie?

Answer 1

`unit\text{ rate = = 18 }(1)/(2)(\min s)/(hr)\text{ (option D)}`

Step-by-step explanation:

`9(1)/(4)\text{minutes of commercial = }(1)/(2)\text{hour of Television}`

A unit rate of minutes of commercials per hour of the movie means to find minute of commercial in 1 hour:

`\begin{gathered} (1)/(2)\text{hour = 9}(1)/(4)\min \\ 1\text{ hour = x} \\ \text{cross multiply: } \\ x((1)/(2))\text{ = 1(9}(1)/(4)) \\ \frac{x}{2\text{ }}=\text{ }(37)/(4)\text{ cross multiply} \\ 4x\text{ = 2}*37 \\ x\text{ = }(74)/(4)\text{ = }(37)/(2) \\ x\text{ = 18 }(1)/(2) \end{gathered}`

The unit rate of minutes of commercials per hour of the movie = 18 1/2 (option D)