SSC GD Constable 15 Feb 2019 Shift 3 Paper

The average of 13 numbers is 65. The average of first three numbers is 63 and that of next 9 numbers is 64.5. The 11^th number is 2 more than the 12^th number but less than 13^th the by 2.5. What is the average of 11^th and 12^th number?