In a mean life of a radioactive sample

Calculate the ratio of half-life to the mean life of a radioactive sample . If lambda be the decay constant of a radioactive sample.

Let T be the mean life of a radioactive sample. 75% of the active nuclei present in th sample initially will deacy in time

The mean life of a radioactive sample is 100 years. Then after 100 years, about -

The mean life of a radioactive sample is 100 years. Then after 100 years, about -

The mean life of a radioactive sample is T_(m) . What is the time in which 50% of the sample woulf get decayed ?

The mean of life of a radioactive sample is 100 years. Then after 100 years, about-

The mean of life of a radioactive sample is 100 years. Then after 100 years, about-