sorry I posted this question before. I have been ill.I still need help. word problem

Question

Upright posts are to be placed at 9 inch intervals on 3 sides of a deck which measures a total of 36 feet. How many upright post will will be needed?
36/3=12, if i divide 12 by 9 it will not give me enough post, so i need to change feet to inches???

Answer 1

of course!
you must have the same units
12/9 would be a meaningless calculation.

36 ft ÷ (9/12) ft = 48

Now, the question is not clear about posts at the end.
e.g. If the fence has one side along a house, would you need a post right against the house at each end?
If so there would be 49 posts,
if not, there would be 47 posts.