A radio-isotope has a half-life of `5` year. The fraction of the atoms of this material that would decay in `15` years will be

Options

A. `1//8`
B. `2//3`
C. `7//8`
D. `5//8`

Answer

C

Explanation

( c) `(N)/(N_0) = ((1)/(2))^(15//5) = (1)/(8) rArr` Decayed fraction `= 1 - (1)/(8) = (7)/(8)`.