If half life period of radium is 1600 years, its average life period will be:

Half life of radium is 1600 years. Its average life:

half life of radium is 1580 years. Its average life will be

Half life period of lead is

The radium and uranium atoms in a sample of uranium mineral are in the ratio of 12.8xx10^(6) . If half life period of radium is 1620 years , the half life period of uranium will be