If `N_(0)` is the original mass of the substance of half - life period `t_(1//2) = 5 year` then the amount of substance left after `15` year is

Options

A. `N_0//8`
B. `N_0//16`
C. `N_0//2`
D. `N_0//4`

Answer

A

Explanation

(a) `N = N_0 ((1)/(2))^((t)/(T_1//2)) = N_0 ((1)/(2))^((15)/(5)) = (N_0)/(8)`.