Insert the missing number.
Answer: Option B
Explanation:
There are two series (8, 11, 14, 17, 20) and (7, 12, 17, 22) increasing by 3 and 5 respectively.
Answer: Option A
Each number is twice the preceding one with 1 added or subtracted alternatively.
So, the next number is (2 x 261 + 1) = 523.
There are two series (10, 13, 16, 19) and (5, 10, 20, 40), one increasing by 3 and the other multiplied by 2.
Each number is the proceeding number multiplied by -2.
So, the required number is -128.
