Let's figure out the area to paint on one target.
The area to paint in white is the middle circle.
Its area is therefore the area of a circle of radius 2*3in minus the area of the red circle inside, which is 3 in (see the attached picture).
Hence the area to paint is A=pi(2*3)^2-pi(3)^2=pi(36-9)=27pi sq in.
Using pi~3.14, A=84.78 square inches
One square inch is approximately 0.006944 square feet hence A=84.78*0.006944=0.5887 square feet.
There are 10 targets to paint thus the total area to paint is 5.887 square feet.
Now for the read area : the read area is the total target's area minus the white area.
Total area of one target : pi*(3+3+3)^2=81*pi~254.34 sq in=1.766 square feet
Hence for 10 targets the total area is 17.66 square feet.
Thus the total area to paint in red is 17.66-5.887=11.773 square feet
You can paint 16 square feet of each paint, hence you have enough paint to do your work.
