Answer:
C. 
Step-by-step explanation:
Hi! Ace here!
In order to do this, we have to convert 18% into a decimal.
The decimal form of it is .18.
So we have to do

Combine like terms:

I hope this helped
Answer:
The value of radius is 7.5 units
Step-by-step explanation:
Given that a line that pass through the origin and form a triangle is a right-angle triangle. So in order to find the diameter/hypotenuse, you have to use Pythogaras Theorem :

Let a = 12 units,
Let b = 9 units,
Let c = hypo.,




We have found out that the hypotenuse of the triangle is the diameter of circle. So in order to find radius, you have to divide it by 2 :



Answer is 7950,72. You can solve it's task on calculator.
7 people, 7 walls, 48 minutes
Each person paints 1 wall in 48 minutes
20 persons, 20 walls
Each can paint 1 wall in 48 minutes so it will
take 48 minutes.