A straight fence is to be constructed from posts 9 inches wide and separated by lengths of chain 5 feet long. If a certain fence begins and ends with a post, which of the following couldnotbe the length of the fence in feet? (12 inches = 1 foot)
Choose the correct choice from the following:
A) 17 B) 28 C) 35 D) 39 E) 40
The fence begins and ends with a post: {post = 0.5 feet}{chains = 5 feet}{post = 0.5 feet}...{chains = 5 feet}{post = 0.5 feet}   The minimum length is with 2 posts = 0.5 + 5 + 0.5= 
<gadget id="calculator">0.5 + 5 + 0.5</gadget>
<output>6</output>
6 feet. To increase the fence, each time we should add{post= 0.5 feet}{chains = 5 feet}, so 5.5 feet. Thus, the lengths could be:   9 feet;   9 + 5.5= 
<gadget id="calculator">9 + 5.5</gadget>
<output>14.5</output>
14.5 feet;   11.5 + 5.5= 20 feet;   17 + 5.5 = 25.5 feet;   22.5 + 5.5 = 31 feet;   28 + 5.5 = 34.5 feet;   33.5 + 5.5 = 41 feet.   ...   We skipped 40 feet.   Answer: 40.
<result>E</result>
A straight fence is to be constructed from posts 9 inches wide and separated by lengths of chain 5 feet long. If a certain fence begins and ends with a post, which of the following couldnotbe the length of the fence in feet? (12 inches = 1 foot)