11
Take the numbers in pairs :-
2 + (4) = 6 . . . add 1 to the first number on this line
3 + (5) = 8 . . . add 3 to the first number on this line
6 + (6) = 12 . . . add 5 to the first number on this line
11
The values added are increasing by one at each stage, and the initial values of each pair are increasing by consecutive odd numbers. The next few entries in the sequence would thus be :-
11 + (7) = 18 . . . add 7 to the first number on this line
18 + (8) = 26 . . . add 9 the the first number on this line
27 + (9) = 36 . . . and so on.
9
The letter is L and the number is 12.
Not sure about completes becasue the series look like it should be infinite. The best continuation is 28, 32, ...
15.
456445
The number which best completes the sequence below is: 2 9 5 13 10 19 17 ?
11
9
What number best completes the sequence 1 1/2 5 10 1/2 18
11
13 20 12
The letter is L and the number is 12.
Not sure about completes becasue the series look like it should be infinite. The best continuation is 28, 32, ...
15.
2 6 3 8 6 12 2 6 3 8 6 12
15, since 15*2 = 9*2 + 12*2
1