There are 6 consecutive odd numbers in increasing order. The difference between the average of the squares of the first 4 numbers and the last 4 numbers is 64. If the sum of the squares of the first and the last element (i.e., odd numbers) is 178, then find the average of all the six numbers.

Options

A. 7
B. 8
C. 9
D. 10

Answer

B