Problem

The decay constant of a radioactive sample is

\lambda

. The half-life and mean life of the sample are respectively given by (JEE 1989) a.

1/\lambda

and

(\ln 2)/\lambda

(\ln 2)/\lambda

and

1/\lambda

\lambda (\ln 2)

and

1/\lambda

\lambda / (\ln 2)

and

1/\lambda