Calculate the time taken to decay `100` percent of a radioactive sample in terms of (a) half- life T and
(b) mean-life `T_(av)`

Explanation

To solve the problem of calculating the time taken to decay 100% of a radioactive sample in terms of half-life \( T_{1/2} \) and mean-life \( T_{av} \), we can follow these steps:

### Step-by-Step Solution:

1. **Understanding the Decay Process**:
- The number of radioactive atoms remaining at time \( t \) is given by the equation:
\[
N(t) = N_0 e^{-\lambda t}
...