JEE Main 20199 Jan, Morning shiftPhysicsHardAtoms and Nuclei183× since 2002
A sample of radioactive material A, that has an activity of 10 mCi(1 Ci = 3.7 10¹⁰ decays/s), has twice the number of nuclei as another sample of a different radioactive materail B which has an activity of 20 mCi. The correct choices for half-lives of A and B would then be respectively :