The answer is 109.
21 + (1 x 28) = 49
22 + (2 x 28) = 78
25 + (3 x 28) = 109
16 21 22 29
The next number in the series 1 2 4 8 10 20 22 is
550
20
20
21 - each number in the series increases by the series 1,2,3,4,5.... Whereby 6 and 7 are separated by 1, 7 and 9 are separated by 2, 9 and 12 are separated by 3, 12 and 16 are separated by 4, so the next in the series would be 21 (16 and 21 are separated by 5).
44
44
13 18 16 21 19 24 22 27 25 ... . This series consists of adding 5 to the first number and subtracting 2 from the next number, repeating the sequence in that order.
16 21 22 29
The next number in the series 1 2 4 8 10 20 22 is
550
25-1=24 24-2=22 22-3=19 19-4=15 15-5=10 The next number in the series is 10.
20
18
39
20