You need to find a common denominator I chose 28 so I multiplied 4 by 7 and that gives you 28 and you have to do the same thing to the top that you did to the bottom so I multiplied 11 by 7 as well which gave me a fraction of 77/28 then I multiplied 7 by 4 to get 28 and multiplied the top by 4 to get a fraction of 20/28 then I added 8 to 20/28 and to 77/28 to get 28/28 (the whole fence) and 85/28 (the paint you need to cover the whole fence) then I simplified my answer by seeing how many times 28 fit into 85 and it fits 3 times with a remainder of 1 so the simplified answer I got was 3 and 1/28 gallons of paint to cover the whole fence.
Step-by-step explanation: it takes him 2 hours to fill 1800 another 2 hours would be 12pm if you have 1000+1000 you get 2000. then add 800 and 800. you get 1600 add them all together you get 3600.