Answer: The correct option is 3, i.e.,40 ft/in.
Explanation:
It is given that the a model rocket is 3 inches long. The real rocket is 120 feet long.
The unit rate which describe the relationship of the real rocket to the model rocket is defined as,
[tex]\frac{\text{Length of real rocket}}{\text{Length of model rocket}}= \frac{120 ft}{3 in.}[/tex]
[tex]\frac{\text{Length of real rocket}}{\text{Length of model rocket}}=40ft/in.[/tex]
This unit rate is shown in option 3, therefore the correct option is 3.
