Samples of two radioactive nuclides, `X` and `Y`, each have equal activity `A` at time `t=0`. X has a half-life of `24 years` and `Y` a half-life of `16 years`. The samples are mixed together. What will be the total activity of the mixture at `t=48` years?

Two samples of the same sradiactive nuclide are prepared. Sample A has twice the initial activity of sample B. How does the hfalf-life of A compare with the half-life of B? After each has passed through five half-lives, what is the ratio of their activities?

Two radioactive substance X and Y initially contain equal number of nuclei. X has a half life of 1 hour and X has a half-life of 2 hours. After the ratio of activity of X to that of y is

Tritium has a half-life of 12.5 years. What fraction of the sample will remain undecayed after 50 years?

The average life of a radioactive sample is 2 years. Its half-life in years is