3, 12, 27, 48, 75, 108,

Answer: Option D

Explanation:

Series is having pattern
\begin{aligned}
3*1^2, 3*2^2, 3*3^2, ......\\
\text{Next will be } 3*7^2 = 147
\end{aligned}

1. 1,2,6,24, ?

Answer: Option C

Explanation:

Pattern is *2, *3, *4
So next number is the series will be *5
24*5 = 120

Answer: Option B

Explanation:

Pattern is +13,+(13*2), +(13*3)
Next will be +(13*4) = 80+52 = 132

Answer: Option A

Explanation:

We can judge that it is A.P.
With 6 as difference
nth term in A.P. = a+(n-1)d
a= 3, n = 21, d = 6
So, 21st term will be = 3+(20)6 = 123

Answer: Option A

Explanation:

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

Answer: Option B

Explanation:

Pattern is, +4, +8, +16, +32, so next will be +64
81+64 = 145