Radioactive decay law, half-life and mean life

2022 Phase 2 1 question

1. Given below are two statements: Statement I: The law of radioactive decay states that the number of nuclei undergoing the decay per unit time is inversely proportional to the total number of nuclei in the sample. Statement II: The half life of a radionuclide is the sum of the life time of all nuclei, divided by the initial concentration of the nuclei at time t = 0. In the light of the above statements, choose the most appropriate answer from the options given below: