Solution:
The pattern is - 45, - 35, - 25, ..... So, missing term = 20 - 15 = 5.

Solution:
The given sequence is a combination of two series: I. 13, 24, 35, 46, 57 and II. 32, 43, ?, 65, 76 The pattern in both I and II is + 11. So, missing term = 43 + 11 = 54.

Solution:
Each term of the series is obtained by multiplying the preceding term by 2. So, 96 is wrong and must be replaced by (64 x 2) i.e. 128.

Solution:
In the first step, one letter from the beginning and one from the end of a term are removed to give the next term. In the second step, two letters from the beginning of a term are removed. These two steps are repeated alternately.

Solution:
The correct pattern is + 2, + 4, + 8, + 16, + 32, + 64 i.e. + 2, + 22, + 23, + 24, + 25, + 26. So, 84 is wrong and must be replaced by (70 + 16) i.e. 86.

Solution:
A + 3 = D + 4 = H + 5 = M + 6 = S + 7 = Z

Solution:
The correct sequence is 52, 72, 92, 112, 132, 152. So, 36 is wrong.