Complete the series, 1, 4, 9, 16, 25,....

Answer: Option D

Explanation:

We can see the given series is in G.P.
as 2*3 = 6, 6*3 = 18, 18*3 = 54
So a = 2 , r = 3
nth term in G.P. is
\begin{aligned}
ar^{n-1} \\
= 2*3{8-1} \\
= 2*3^7 \\
= 2*2187 = 4374
\end{aligned}

Answer: Option B

Explanation:

There are two series in this sequence
Series 1: 13, 24, 35, 46, 57
Series 2: 32, 43, (..), 65, 76

The pattern it is following is +11
Missing number will be 43 + 11 = 54

Answer: Option A

Explanation:

Pattern in the series is *2+1, *2+2, *2+3,.....

Term which replaces the question mark in the series is
121 * 2 + 6 = 248

Answer: Option C

Explanation:

Please note that above sequence is containing 3 series
Series 1 : 8, 7, 6, (..)
Series 2 : 9, 10, 11, 12
Series 3 : 8, 9, 10

In series 1 pattern is -1. So missing term will be 6-1 = 5

Answer: Option B

Explanation:

Pattern in the series is, +5, +9, .., .., +21, +25
So 4 is getting increased at every term addition.
Missing term in the series will be 15+(9+4)
= 15+13 = 28