16, 33, 65, 131, 261, (....)
Answer: Option A
Explanation:
Each number is twice the preceding one with 1 added or subtracted alternatively.
So, the next number is (2 x 261 + 1) = 523.
10, 5, 13, 10, 16, 20, 19, (....)
Answer: Option B
1, 4, 9, 16, 25, 36, 49, (....)
Answer: Option C
Numbers are 12, 22, 32, 42, 52, 62, 72.
So, the next number is 82 = 64.
2, 4, 12, 48, 240, (....)
Go on multiplying the given numbers by 2, 3, 4, 5, 6.
So, the correct next number is 1440.
8, 7, 11, 12, 14, 17, 17, 22, (....)
There are two series (8, 11, 14, 17, 20) and (7, 12, 17, 22) increasing by 3 and 5 respectively.