The equation will be of the form:

where A is the amount after t hours, and r is the decay constant.
To find the value of r, we plug the given values into the equation, giving:

Rearranging and taking natural logs of both sides, we get:


The required model is:
Answer: B
Step-by-step explanation:
The area which is not in used for the flower gardens is 10964 sq ft.
Step-by-step explanation:
Given,
Length (l) of the rectangular park = 160 ft
Width (b) of the rectangular park = 80 ft
Length (l) of each rectangular flower garden = 18 ft
Width (b) of each rectangular flower garden = 17 ft
To find the area which is not in used.
Formula
The area of rectangle = l×b
Now,
The area of the rectangular park = 160×80 sq ft = 12800 sq ft
The area of each rectangular flower garden = 18×17 sq ft = 306 sq ft
The area of 6 rectangular flower garden = 306×6 sq ft = 1836 sq ft
So,
The area which is not in used = 12800-1836 sq ft = 10964 sq ft.
0.375 is the answer because there are 3 0's in COLORADO and 8 letter's in total. The fraction part would be 3/8 and in decimals it is 0.375.