The pattern is :
8 × 2 + 2 = 16 + 2 = 18
18 × 2 + 4 = 36 + 4 = 40
40 × 2 + 6 = 80 + 6 = 86
.......... and so on.

Correct Option: A

The pattern is :
8 × 2 + 2 = 16 + 2 = 18
18 × 2 + 4 = 36 + 4 = 40
40 × 2 + 6 = 80 + 6 = 86
86 × 2 + 8 = 172 + 8 = 180 ≠ 178
Since , 178 is wrong term . so , 180 is correct term .
Thus , required answer is 178.
180 × 2 + 10 = 360 + 10 = 370

The pattern is :
3 × 2 + 2 = 6 + 2 = 8
8 × 3 + 3 = 24 + 3 = 27
27 × 4 + 4 = 108 + 4 = 112
112 × 5 + 5 = 560 + 5 = ?

Correct Option: A

The pattern is :
3 × 2 + 2 = 6 + 2 = 8
8 × 3 + 3 = 24 + 3 = 27
27 × 4 + 4 = 108 + 4 = 112
112 × 5 + 5 = 560 + 5 = ?
∴ ? = 565
Thus , The next number of the sequence is 565 .

The pattern is :
1³ – 1 = 1 – 1 = 0
2³ – 1 = 8 – 1 = 7
3³ – 1 = 27 – 1 = 26
4³ – 1 = 64 – 1 = 63
5³ – 1 = 125 – 1 = 124

Correct Option: A

The pattern is :
1³ – 1 = 1 – 1 = 0
2³ – 1 = 8 – 1 = 7
3³ – 1 = 27 – 1 = 26
4³ – 1 = 64 – 1 = 63
5³ – 1 = 125 – 1 = 124
6³ – 1 = 216 – 1 = 215 ≠ 217
Since , 217 is wrong term . so , 215 is correct term .
Thus , required answer is 217.

The pattern is :
3 × 6 = 18
18 – 6 = 12
12 × 6 = 72
72 – 6 = 66
66 × 6 = 396
396 – 6 = ?

Correct Option: D

The pattern is :
3 × 6 = 18
18 – 6 = 12
12 × 6 = 72
72 – 6 = 66
66 × 6 = 396
396 – 6 = ?
∴ ? = 390
Hence , the missing number in given series is 390 .

The pattern of the sequence is :
169 = 13²
144 = 12²
121 = 11²
100 = 10²
........... and so on.

Correct Option: D

The pattern of the sequence is :
169 = 13²
144 = 12²
121 = 11²
100 = 10²
81 = 9² ≠ 82
From above it is clear that fifth term 82 is wrong .So , correct number is 81 which is square of 9 number .Thus , required answer is 82 .