The answer is B I agree with him/her
To find the answer to that, you have to see how many numbers are between 13 and 31. There are 18 numbers between 13 and 31. Divide 18 by 2 and you will get the number halfway. 9 is halfway between 13 and 31. So, add 9 to 13 and you get 22.
The answer is 22.
Hope I helped
The answer for the question is 8.33
I believe it's 9x2-12x+4 but I'm not quite sure cause we haven't yet gone over this in class.
My friend also believes it is this (she's in a higher level math grade than me). I'm so sorry this isn't more helpful.