if 1/2 a gallon of paint covers 1/3 of the wall, then adding two more, would be adding two more so two more things of 1/2 gallon paints, would be 1 1/2 gallon of paint
You would do 20-6 which = 14. + 1 =15. times 8= 120 then divide that by 1/2 = 240 if you do 120 divided by .5 in a calculator thats what you get. i hope that helps you
