Which number will come next in the following series? 1, 3, 7, 15, 31, 63, .......

Options

A. 129
B. 127
C. 125
D. 126

Answer

B

Explanation

It follows the series `2^n -1,` where `n = 1,2,3,4.......`
So, next term will be ` = 2^7-1 = 127`.
Option B is correct.