1 1/8:3/7
How many gallons does it take to cover 1/7 of the fence?
1 1/8 divided by 3= 9/8 divided by 3/1 or 9/8*1/3=9/24 or 3/8.
It takes 3/8 of a gallon to paint 1/7 of a fence.
7*3/8= 7/1*3/8= 21/8.
I believe your answer is: it takes 21/8 or 2 5/8 gallons of paint to paint the whole fence.