So he started with 3/4 lb and ended up with 2/3 of that so 2/3 of 3/4 'of' can be roughly translated as multiply so 2/3 times 3/4 =6/12=1/2 lb left or you know that there are 3 out of 4 parts pound left so 2 out of 3 parts of nuts is = 2/4 or 1/2 lb
There are 10 feet of posts on each side. That means there are 40 feet of fencing in total. If you divide that by two (to represent posts being 2 feet apart) then you get 20. There are 20 posts needed.
