Question

A model rocket is 3 inches long. The real rocket is 120 feet long.

What is the unit rate that describes the relationship of the real rocket to the model rocket?

A. 360 ​ in./ft ​
B. 40 in./ft
C. 40 ft/in.
D. 360 ​ ft/in. ​

Answer 1

The units are the complete story on this question. All of the choices are over 1 so the units make the answer over one. It takes more feet than it does inches to make the scale. The correct units are 120 feet / 3 inches. That makes A and B both incorrect.

You can't get 360 by any method but multiplication. The units for multiplication would be ft*in. So D is wrong. That only leaves you with C which is the answer.