6, 11, 21, 36, 56, ?
what will replace the question mark in the series ?

Answer: Option B

Explanation:

Pattern is +5, +10, + 15, +20

Next number in the series will be 56 + 25 = 81

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 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:

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:

Please look carefully at the series, its pattern is,
-1, +2, -1, +2, -1, so next will be +2
23+2 = 25