The details of the packages are not posted, however I can tell you how to find the answer.
First determine how many pencils are in each pack.
Then divide the price of the pack by the number of pencils to find out which pack has the least cost per pencil. To put this in equation form:

Whichever pack has the least cost per pencil is the one that is the best priced.
That would be 19. I belive this bc 9 plus 9 is 19 and no matter what combination of boxes you will not have 19 chiken nugets
0 and 5 can be in the one's place of a number that has 5 as a factor.
<u>Answer:</u>
11. g
12. f
13. e (add all the frequencies)
14. d
15. c (eg. 17.5 -8.5 = 9)
16. b
17. a
Let me know if you have any questions.
Hope this helps!