The average of 20 numbers is 65. The average of the first 9 numbers is 68 and the average of next 8 numbers is 62. If the $$18^{th}$$ number is 3 more than $$19^{th}$$ number and 9 less than $$20^{th}$$ number. then what is the average of $$19^{th}$$ and $$20^{th}$$ number?

A

64.5

B

66

C

65

D

65.5