8, 10, 14, 18, (...), 34, 50, 66

Answer: Option A

Explanation:

Pattern is +5, +10, +15, + 20. So next will be 56+25 = 81

Answer: Option C

Explanation:

Please check the given sequence is combination of two series.
Series 1: 19, 38, 114, ...
Series 2: 2,3,4

In series 1, Pattern followed is *2, *3, so next will be *4
Next term will be
114*4 = 456

Answer: Option A

Explanation:

Pattern in the series is, -2, -4, -2, -4. So next term will be -2
24 -2 = 22

Answer: Option C

Explanation:

Patten is +2, +4, +4, .., .., +16, +16

Missing number will be 18+8 = 26

Answer: Option C

Explanation:

\begin{aligned}
\text{Pattern is }\\
+1^2-1, +2^2-1, +3^2-1,+4^2-1 \\
5^2-1 = 28 + 24 \\
= 52
\end{aligned}