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

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 B

Explanation:

Above series contains prime number series. So after 11, 13 is next prime number.

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 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 C

Explanation:

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

Missing number will be 18+8 = 26