Here a = 8 and b = 13
The numbers in the Fibonacci sequence are arranged in the following manner:
1st, 2nd, (1st+2nd), (2nd+3th), (3th+4th), (4th+5th), (5th+6th), (6th+7th), (7th+8th), (8th+9th), (9th+10th)
The numbers are 8, 13, 21, 34, 55, 89, 144, 233, 377 and 610.
Sum of the numbers = 8+13+21+34+55+89+144+233+377+610
=1584
11×7th number = 11×144=1584