Physics

Problem

Two radioactive materials

A_1

and

A_2

have decay constant

5\lambda

and

\lambda

respectively. If initially they have the same number of nuclei than ratio of nuclei of

A_1

A_2

will be

\frac{1}{e}

after a time: a.

\frac{1}{4\lambda}

\frac{e}{\lambda}

\lambda

\frac{\lambda}{2}