Calculate the average of all the numbers between 10 and 86 which are divisible by 9.  Select the correct option
A) 49.5 B) 41.5 C) 45.5 D) 40.5 E) 47.5

Rationale: "explanation : numbers divisible by 9 are 18,27 , 36,45 , 54,63 , 72,81 , average = ( 18 + 27 + 36 + 45 + 54 + 63 + 72 + 81 , ) / 8 = 396 / 8 = 49.5 answer : a"
Answer: A