The ratio that compares the measurements of a model and the real object is called what?

Unit Scale

Step-by-step explanation:

A unit scale is a ratio that compares the dimensions of an actual object to the dimensions of a scale drawing or model that represents the actual object. Neither value in a unit scale has to equal 1.

f(x) has value 150 at x= 0

and 0 at x= 3

so d(f(x))/dt = slope = -150/3 = -50

i think the answer is b