I have no idea about the part A, but part b, all you have to do is get all the numbers of the fans, and put them in least to greatest. Then you count how fans are from 0-9, then you count how much fans are from 10 - 19, and so on. Im sorry that i couldn't answer it completely but i hope this helps.
Answer:
C 152
Step-by-step explanation:
Beacuse it is. Hope that helps