The formula of a midpoint between E and F:

We have the points
and
. Substitute:

Answer: 
Divide 30 by 3 and you get 10. Divide 30 by 2 and your get 15. Add 15 to 10 and you get 25. 25 is your answer.
The probability of not rolling a 2 is 5/6, since the probability of rolling a 2 is 1/6.